Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: JamesV6CDX on 16 May 2010, 10:08:20
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Our flight arrived on schedule in Inverness at 14:25 yesterday afternoon, to collect a facelift Elite that was described as "mechanically perfect".
I'd taken a chance, and bought the thing unseen.. so I'm not grumbling... however, that description wasn't quite correct.
I'm not looking to moan, and have no intention of looking of recourse - I'm just after some opinions on fixing the damn thing.
First issue - drivers seat was right back, and wouldn't adjust. After spending an hour with various implements removing coins from the seat runners, I fixed that. Ahh - ready to drive back at last!
First thing I noticed, was a misfire at idle. I now realised why the guy bu99ered off so quickly ;D knowing I had 650 miles to do in it.
Popped a lead off each side, tiny trace of oil but no contamination, they looked OK. Didn't have tools to investigate any further. I filled up with petrol and decided to do a few miles down the road to get a better picture.
At cruising speed - seemed OK! Just appeared to be missing at idle, and under load. I then decided nothing for it - will run the gauntlet for home. This turned out to be a bad idea :-[
I managed just shy of 400 miles - got from Inverness, down onto the M6.
I noticed during this time that the baffles must have let go in the exhaust - awful noise.
As I joined the M6, I noticed the fuel gauge appeared to have gone quite low, quite quickly. It went to red, and started flashing before I knew what had happend. Hmm.
Stopped at a garage. Revved the engine while outside the car - and it stank of petrol. Especailly at the rear. Had a look and couldn't really see any leaks.
It was misfiring - properly, at this time. Guessed it was unburnt fuel. Decided to take it to service area 17 miles down the M6, get some coffee and arrange recovery.
I put £40 of petrol in, and set off on the 17 mile run. As I took the petrol cap off to re-fill, there seemed to be a LOT of vapour type stuff coming out of the filler neck.
Drove on to next services - again, she seemed to cruise OK.
Bearing in mind I put in £40 - which took it to half a tank, it USED THE LOT, over 17 miles. Gauge flashing again, at the next stop :o :o
- now even if it's mis firing - this is like 2 miles per gallon - surely all that petrol couldn't have gone in the engine, over this time :o
When I stopped again, I looked underneith, and the 2-4-6 side cat was glowing, absolutely red hot!!!
Is this pointing to a blockage - or is it unburnt fuel?
My thinking is, I will need -
Plugs
Lead check
DIS Pack
Good pair of cats
Eternalcar catback exhaust
Probably knackered the lambdas too.
Otherwise - the car's very nice ;D
Fixing the misfire I'm sure won't be a problem, but, I am thrown by the fact that SO MUCH fuel disappeared over 17 miles, with no trace of an external leak.
Opinions welcome, please :y
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Are you sure there's not a leak? You wouldn't use half a gallon a mile even if your foot was going through the floor! :o :o
Hope you have better luck soon buddy :y
Jon
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any air leaks around the plenum? Had that with 3.2 other day, o-ring got caught under plenum caused mis-fire and red hot cat.
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Are you sure there's not a leak? You wouldn't use half a gallon a mile even if your foot was going through the floor! :o :o
Hope you have better luck soon buddy :y
Jon
Positive.
Lie under it with engine running, shining a torch - can see no leaks around tank, fuel lines, or in engine bay. The exhaust, however, stinks of fuel, and it's all up the back window of the car.
I kid you not - £40 gone over 17 miles... :-/
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I think it's time to use a bit of your expertise and start dimantling things mate, Tunnie's suggestion seems a good place to start, and air filter etc.
And finding which cylinder is misfiring. Still wonder how so much fuel is being used though
Jon
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I put £40 of petrol in, and set off on the 17 mile run. As I took the petrol cap off to re-fill, there seemed to be a LOT of vapour type stuff coming out of the filler neck.
Normally the rear silencer doesn't get get terribly hot. If one cat was red hot is it possible that the rear silencer was unusually hot to & causing the fuel tank to get unusually hot?
Is it also possible that a hot fuel tank was venting your petrol onto the road?
What I'm trying to say is that poor running issues causing outrageous overheating over several hours on the motorway may have caused a vapour pressure problem in the tank which may never happen again.
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Still wonder how so much fuel is being used though
Jon
That's the one thing that is really puzzling me, and, is the stumbling block I have hit.
If it wasn't for this, I would have treated as basic misfire and diagnosed accordingly.
I guess all I can do, to quote MDTM, is fix the known issues, and take it from there... :-/
Problem is, I now have a Nissan "Note", and my Miggy probably won't reach me for a few days ::)
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What I'm trying to say is that poor running issues causing outrageous overheating over several hours on the motorway may have caused a vapour pressure problem in the tank which may never happen again.
I had a simelar idea on the way back mate, but having been up for 24 hours can't get my head around it....
I'm guessing there was obviously extreme pressure in the tank, I thought this, when I saw the vapour.
I'm just a bit unsure as to how a misfire would cause it - the backbox didn't feel all that hot :-/
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Way out West....you could be looking at two different issues re that misfire. How bad are we talking misfire wise ( any more than norm for an Omega?)
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Hmm,
for what its worth!!!
I personally would go back to basics and do a full service including fuel filter, as a weak mixture will also cause hot cat and could well cause a missifre, untill you have caried this ot along with basic checks(coilpack leads etc and had a proper ;look its no good guessing at what the problem is! process of elimination by full service and checks should gove you a new perspective on it!!
:y
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There was also a "whoosh" noise on accelerating, which sounded like an exhaust blockage to me...
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Mmm, that is a shame James...I'm suprised by how many private sellers lie through their teeth when selling their car.
As Tunnie mentioned, on my 3.2 after a few minutes, if that, the cat was glowing red hot due to an air leak.
And I think you have every right to grumble, don't forget that you're mechanically aware...what would someone else think if they used that much fuel in 17 miles, and part of their exhaist was red hot? To them it'd be rather bad. They'd be straight on the phone to the seller. Not suggesting causing a fuss, but maybe let him know of the situation...he may feel obliged to offer assistance, be that maybe with £50 back.
I guess 3.2 cats won't fit a 3.0? Exhaust manifolds and other stuff is probably different? If they do fit, you're more than welcome to try my 3.2 cats on your 3.0 to see if that makes any difference.
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One thing might be worth a look is it just one cat glowing if so check the plug leads on that side are connected to the correct plugs if not this will give you both the misfire at low revs and unburnt fuel inthe cat which will burn and make it glow. I know from experience after changing my rocker covers and getting them mixed up.
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I'm going to pop the plenum off tomorrow night and have a good old look :)
If that is the case, it would imply it's been bodged about with, and I will definately let the guy know what I found.
Moving on, however - I have got a couple of new cats on the way, new DIS, new LEADS, new plugs, new stat... so she's in for a treat ;D
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hi
from my own experience on a different car i would reckon its your ht leads not connected to the right plugs
this would cause a misfire and also make the exhaust hot to a point where it is glowing
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hi
from my own experience on a different car i would reckon its your ht leads not connected to the right plugs
this would cause a misfire and also make the exhaust hot to a point where it is glowing
Either that, or, a straightforward misfire causing the same effect, by say, a failed coil pack?
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James - I had a very similiar experience in a V8 BMW 7 series after having the gearbox serviced, lumpy idle that gradually got worse as I drove her, massive fuel consumption, almost managed to get the 10 miles home when the motorist behind me starting flashing his headlights and when i pulled over and had a look at the back of the car the 2 tailpipes were glowing red hot!!! they were so hot that the bumper ignited and luckily I had an extuinguisher, anyway cut a long story short I had an engineer look at the car and he found that the garage had dropped the exhuast to access the gearbox and when re-fitting they had mixed up the lamda sensor plugs and the ECU was detecting a problem on the mixture and sending loads of fuel into a red hot exhuast - I would check those mate as it all sounds horribly familiar :y
Regards
Darren
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Had a similar problem with an 04 bmw 525i,bad misfire and neat fuel out of the exhaust,single figure fuel consumption and it turned out to be a stuck injector that would not stop fuelling.
luckily for the owner he stopped the car and it would not restart as it was trying to hydraulic with all the fuel in the cylinder,to my surprise one new injector cured it
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Now you mention plug lead order - he did say the cam cover gaskets had been done recently.
I just wonder, if it's been like it ever since, due to no 4 and 6 leads being crossed by a silly mechanic.... and is why he got rid :-X
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All 6 spark plugs very black
Leads and DIS visually look OK. A tiny amount of water ingress in no6.
Valve timing checked - spot on. whoever last did it, knows how it's done.
No antifreeze mix, has been running neat water for some time.
Breathers quite blocked and TBs need a good clean.
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fuel rail pressure to high? release valve/pipe troubles? :-?
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fuel rail pressure to high? release valve/pipe troubles? :-?
I don't know. The rear of the car smells of petrol. I am quite thrown by ALL plugs being black. I was expecting just a couple..
What does this indicate - more fuel going in, than the plugs can cope with?
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fuel rail pressure to high? release valve/pipe troubles? :-?
I don't know. The rear of the car smells of petrol. I am quite thrown by ALL plugs being black. I was expecting just a couple..
What does this indicate - more fuel going in, than the plugs can cope with?
Do you mean unburnt fuel from the end of the exhaust, or a smell of fuel arround the tank.
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fuel rail pressure to high? release valve/pipe troubles? :-?
I don't know. The rear of the car smells of petrol. I am quite thrown by ALL plugs being black. I was expecting just a couple..
What does this indicate - more fuel going in, than the plugs can cope with?
Do you mean unburnt fuel from the end of the exhaust, or a smell of fuel arround the tank.
Both
There is some evidence of fuel running down the back of the tank.
The rear window, is also covered in petrol mist.
This, with the amount of vapour coming from the fuel filler when I removed it after a drive... indicates the pressure in the fuel tank, is WAY too high, and maybe it's vented, somewhere!
I'm confused as to what could cause that much pressure in the fuel system though
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light brown plugs=ok
very white plugs=weak mixture
black plugs=unburnt fuel
if one plug was black then as the bmw owner said, one injector.( ht side assumed ok)
all plugs, all cylinders getting to much fuel.
fuel rail pressure has to adjust to match plenium chamber pressure. (full throttle/idle)
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fuel rail pressure to high? release valve/pipe troubles? :-?
I don't know. The rear of the car smells of petrol. I am quite thrown by ALL plugs being black. I was expecting just a couple..
What does this indicate - more fuel going in, than the plugs can cope with?
Do you mean unburnt fuel from the end of the exhaust, or a smell of fuel arround the tank.
Both
There is some evidence of fuel running down the back of the tank.
The rear window, is also covered in petrol mist.
This, with the amount of vapour coming from the fuel filler when I removed it after a drive... indicates the pressure in the fuel tank, is WAY too high, and maybe it's vented, somewhere!
I'm confused as to what could cause that much pressure in the fuel system though
the tank is obviously not being vented as you say and it should be, fuel returning to the tank has nowhere to go (pressure build up) how does it run with the fuel cap off?
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Not tried with cap off, yet.
What could cause it though? something blocked? If so, what?
Or, what about the FPR? Could that do it?
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Has it had a new tank fitted, are the returns and vent pipes blocked or incorectly fitted.
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Has it had a new tank fitted, are the returns and vent pipes blocked or incorectly fitted.
Not that I know of.... doesn't look new. :-/
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Has it had a new tank fitted, are the returns and vent pipes blocked or incorectly fitted.
Not that I know of.... doesn't look new. :-/
Be tempted to at least check the whole return system, sounds like you are driving an armed bomb arround. :-/
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some motors position the vent in a stupid place (wheel arch )that can block with dirt. (not sure on the mig set up)
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some motors position the vent in a stupid place (wheel arch )that can block with dirt. (not sure on the mig set up)
Can anyone confirm, please?
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some motors position the vent in a stupid place (wheel arch )that can block with dirt. (not sure on the mig set up)
Can anyone confirm, please?
I haven't actually seen it but...
When the engine is off the fuel tank vents through a charcoal canister hidden above the wheelarch liner in the front drivers side wheel arch. The charcoal absorbs petrol fumes to prevent them escaping to atmosphere.
When the engine is running the charcoal cannister purge valve opens and manifold vacuum pulls air through the charcoal to purge it of fuel fumes.
If the fuel tank became pressurised then that could a give a route for petrol straight into the inlet manifold.
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some motors position the vent in a stupid place (wheel arch )that can block with dirt. (not sure on the mig set up)
Can anyone confirm, please?
I haven't actually seen it but...
When the engine is off the fuel tank vents through a charcoal canister hidden above the wheelarch liner in the front drivers side wheel arch. The charcoal absorbs petrol fumes to prevent them escaping to atmosphere.
When the engine is running the charcoal cannister purge valve opens and manifold vacuum pulls air through the charcoal to purge it of fuel fumes.
If the fuel tank became pressurised then that could a give a route for petrol straight into the inlet manifold.
Many thanks for this, still doesn't explain why the excess pressure is in the system in the first place, though? :-/
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some motors position the vent in a stupid place (wheel arch )that can block with dirt. (not sure on the mig set up)
Can anyone confirm, please?
I haven't actually seen it but...
When the engine is off the fuel tank vents through a charcoal canister hidden above the wheelarch liner in the front drivers side wheel arch. The charcoal absorbs petrol fumes to prevent them escaping to atmosphere.
When the engine is running the charcoal cannister purge valve opens and manifold vacuum pulls air through the charcoal to purge it of fuel fumes.
If the fuel tank became pressurised then that could a give a route for petrol straight into the inlet manifold.
Many thanks for this, still doesn't explain why the excess pressure is in the system in the first place, though? :-/
I thought you were going to reserve judgement on that until you had checked :
- blocked cats
- blocked silencers
- crossed over plug leads
- crossed over lambda sensors
I still think that your fuel tank got very hot :o
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Leads - checked
Plugs - checked (black)
Lambda connections - checked
You may be right. I will run it up with new leads and dis, and we'll see where the land lies then.
New cats and new cat back exhaust is on order
:y
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vapours are drawn into the plenium as stated, but to suck fuel out and return to the tank require atmospheric vent.
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vapours are drawn into the plenium as stated, but to suck fuel out and return to the tank require atmospheric vent.
And where does this vent, any ideas?
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Our flight arrived on schedule in Inverness at 14:25 yesterday afternoon, to collect a facelift Elite that was described as "mechanically perfect".
I'd taken a chance, and bought the thing unseen.. so I'm not grumbling... however, that description wasn't quite correct.
I'm not looking to moan, and have no intention of looking of recourse - I'm just after some opinions on fixing the damn thing.
First issue - drivers seat was right back, and wouldn't adjust. After spending an hour with various implements removing coins from the seat runners, I fixed that. Ahh - ready to drive back at last!
First thing I noticed, was a misfire at idle. I now realised why the guy bu99ered off so quickly ;D knowing I had 650 miles to do in it.
Popped a lead off each side, tiny trace of oil but no contamination, they looked OK. Didn't have tools to investigate any further. I filled up with petrol and decided to do a few miles down the road to get a better picture.
At cruising speed - seemed OK! Just appeared to be missing at idle, and under load. I then decided nothing for it - will run the gauntlet for home. This turned out to be a bad idea :-[
I managed just shy of 400 miles - got from Inverness, down onto the M6.
I noticed during this time that the baffles must have let go in the exhaust - awful noise.
As I joined the M6, I noticed the fuel gauge appeared to have gone quite low, quite quickly. It went to red, and started flashing before I knew what had happend. Hmm.
Stopped at a garage. Revved the engine while outside the car - and it stank of petrol. Especailly at the rear. Had a look and couldn't really see any leaks.
It was misfiring - properly, at this time. Guessed it was unburnt fuel. Decided to take it to service area 17 miles down the M6, get some coffee and arrange recovery.
I put £40 of petrol in, and set off on the 17 mile run. As I took the petrol cap off to re-fill, there seemed to be a LOT of vapour type stuff coming out of the filler neck.
Drove on to next services - again, she seemed to cruise OK.
Bearing in mind I put in £40 - which took it to half a tank, it USED THE LOT, over 17 miles. Gauge flashing again, at the next stop :o :o
- now even if it's mis firing - this is like 2 miles per gallon - surely all that petrol couldn't have gone in the engine, over this time :o
When I stopped again, I looked underneith, and the 2-4-6 side cat was glowing, absolutely red hot!!!
Is this pointing to a blockage - or is it unburnt fuel?
My thinking is, I will need -
Plugs
Lead check
DIS Pack
Good pair of cats
Eternalcar catback exhaust
Probably knackered the lambdas too.
Otherwise - the car's very nice ;D
Fixing the misfire I'm sure won't be a problem, but, I am thrown by the fact that SO MUCH fuel disappeared over 17 miles, with no trace of an external leak.
Opinions welcome, please :y
cats giving up and being blown out of the back exhaust due to working so hard?
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Maybe - but still I can't link this to the cause of the fuel excess pressure?
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Do the V6's have a coolant temp.sensor that signals the ECU?had a few rover 820/vitesse's that ate the things but when they went wrong they gave a misfire and acquired a thirst like a v12.
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I have vents in the rear off side wheel arch on my Elite
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Sounds like massive overfuelling to me, so try with the MAF disconnected.
Does it misbehave from cold or just when hot?
If just when hot, try unplugging the Lambdas.
Failing that, high fuel pressure? FPR / blocked fuel return line.
Maybe a stuck open injector (all plugs will be black after a cold start or period of idling. Check for a very wet one).
Only vent from fuel tank is into breather box so that can be disconnected from the purge valve to eliminate it.
Check the oil for fuel contamination too.
Kevin
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Sounds like massive overfuelling to me, so try with the MAF disconnected.
Will do!
Does it misbehave from cold or just when hot?
I've never driven it from stone cold. When I picked it up, the engine was warm, and a slight misfire.
It was only when I had been cruising at semi-naughty motoway speeds for an hour or two, that the massive fuel consumption started.
If just when hot, try unplugging the Lambdas.
Again - will do!
Failing that, high fuel pressure? FPR / blocked fuel return line.
Again, this was my school of thought. However, if the return line was blocked somehow, would I have stilll seen all the vapour from the neck of the tank?
Maybe a stuck open injector (all plugs will be black after a cold start or period of idling. Check for a very wet one).
No 4 seemed quite wet. Couldn't tell if this was a result of petrol, or water ingress in the plug recess, though....
Only vent from fuel tank is into breather box so that can be disconnected from the purge valve to eliminate it.
Check the oil for fuel contamination too.
Kev - many thanks. I will check these things later and report back :y
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Remove the fuel pump insepction plate in the boot and check for damage and/or excessive corrosion around the plate on top of the tank.
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Remove the fuel pump insepction plate in the boot and check for damage and/or excessive corrosion around the plate on top of the tank.
Will do, Mark - I like nice easy jobs like that :D
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Yeh well....that would give a poor fuel supply which can give a lean mix which in turn makes it run hot.
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Yeh well....that would give a poor fuel supply which can give a lean mix which in turn makes it run hot.
Thanks Mark... do you think that could be related to the excess fuel pressure?
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Yeh well....that would give a poor fuel supply which can give a lean mix which in turn makes it run hot.
Thanks Mark... do you think that could be related to the excess fuel pressure?
How do you know you have excess fuel pressure......or are you refereing to the tank pressure?
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Yeh well....that would give a poor fuel supply which can give a lean mix which in turn makes it run hot.
Thanks Mark... do you think that could be related to the excess fuel pressure?
How do you know you have excess fuel pressure......or are you refereing to the tank pressure?
In honesty Mark, I'm basing it on -
A) The fact there is some evidence of some petrol running down the back of the tank.
B) When I removed the filler cap, there seemed to be loads of pressure in the tank. (I thought this, due to the amount of petrol smelling vapour that came out, when I removed the filler cap)
c) I (still) cannot get my head around, where 40 litres of fuel went, in 15 miles :(
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I suspect it went over the road due to a leak around these pipes...... :y
Its certainly the first thing to check as its quick and easy to do
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First job, then :y
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I was wondering if the fuel consumption could be the fuel pump nspection tank. When it was off on my tractor, I had diesel covering the back of mine, which obviously gave me a strong diesel smell... It also gave quite a strong smell in the car, but then, I wasn't doing motorway speeds...
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This is a petrol one though. Would the problems not be different between petrol and diesel.
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This is a petrol one though. Would the problems not be different between petrol and diesel.
I think the tank setup is roughly the same, though? Not 100% sure.
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Sounds like massive overfuelling to me, so try with the MAF disconnected.
Does it misbehave from cold or just when hot?
If just when hot, try unplugging the Lambdas.
Failing that, high fuel pressure? FPR / blocked fuel return line.
Maybe a stuck open injector (all plugs will be black after a cold start or period of idling. Check for a very wet one).
Only vent from fuel tank is into breather box so that can be disconnected from the purge valve to eliminate it.
Check the oil for fuel contamination too.
Kevin
Are you sure?
The idea of the purge valve connection to the plenum is to pull fresh air through the carbon canister to purge it of fuel fumes. Ergo there must be a permanently open vent of some kind on the canister in addition to the connections for the tank and the purge valve. :-/
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UPDATE
Tonight I changed the DIS pack, plugs, and leads, for brand new components. All OE stuff unfortunately, VX prices would have been prohibitive. But nonetheless proven on other cars.
I then removed the plate mark suggested, and checked the fuel connections on top of the tank. They are definately quite corroded, BUT, secure and not leaking.
I tried to start her up after this - just wouldn't go. I ended up flattening the battery. Put a can of petrol in - still nothing, despite the fact there was pressure in the rail when the release valve was pressed, and a spark on all plugs.
Charged battery for a bit, and got 2 more cans of petrol. After a lot of cranking and coughing, she then fired up.
At this point, I had a result!
She fired into life, misfire totally gone, smooth as silk. Comparable to a 40k mile engine.. really quiet, and responsive to the throttle (when I'd let it warm up, obviously!) 8-)
I let her idle for a bit on the driveway.. exhaust sounded... wrong. Blocked. I cable tied a rubber glove to it, and it wouldn't inflate the glove!!!!!
After letting it idle, I had a look under the fuel tank. Couldn't see any drips etc.
Took her for a spin around the block, I had covered half a mile, when the guy behind flagged me down.
"Your car's pissing fuel everywhere mate!" ;D
Had a look, sure enough, puddle underneith. Inspection area still all dry though. Though I could smell petrol if I put my nose to it.
There seems to be a fuel mist everywhere... I am thinking, possible pin hole somewhere???
Now the engine runs so well, I just wonder if in fact, the fuel thing is unrelated, and an unfortunate co-incidence... :-/
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I'd work with the known issue first, unblock the exhaust, it surely can only be the cat or the silencer collapsed?
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I'd work with the known issue first, unblock the exhaust, it surely can only be the cat or the silencer collapsed?
Yep, I have a new pair of cats and complete new exhaust on order :y
Blocked exhaust wouldn't cause a major fuel leak though, would it? :-/
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Well if it can't blow up a rubber glove then what's happening to all the exhaust? the back pressure must be incredible.
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Well if it can't blow up a rubber glove then what's happening to all the exhaust? the back pressure must be incredible.
Oh I agree for sure, it needs to be sorted before it can be used on the road.
I'm just struggling to link it to the fuel issue, though :-/
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assumption is the mother of all...
they may well be seperate issues.
both detrimental to fuel comsumption. :-?
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Is the fuel filter fitted the right way?
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Sod the exhaust at the moment..........the NUMBER 1 issue to fix is the fuel leak....so now the cover looks ok, check the pipes and fuel filter, is the filter new and ok (I have seen them that old that the side rots out on them!).
Now you know the real reason why the consumption was bad.....its pissing it ll over the road
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Are the fuel flow/return lines connected the right way round to the inlet manifold? Would it make any difference if it were wrong?
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Are the fuel flow/return lines connected the right way round to the inlet manifold? Would it make any difference if it were wrong?
If they were back to front then the pump would have to push the fuel the wrong way through the pressure regulator & then into the fuel rail. Once there it could flow straight back to the tank so there would be no pressure at the injectors. I don't think the engine could run at all TBH
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Sod the exhaust at the moment..........the NUMBER 1 issue to fix is the fuel leak....so now the cover looks ok, check the pipes and fuel filter, is the filter new and ok (I have seen them that old that the side rots out on them!).
Now you know the real reason why the consumption was bad.....its pissing it ll over the road
Is it possible that the fuel leak and the exhaust blockage are related? As has been pointed out the back pressure has to be immense and will need to vent somewhere... Could it be pressurising the fuel return pipe, perhaps rupturing that?
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Sod the exhaust at the moment..........the NUMBER 1 issue to fix is the fuel leak....so now the cover looks ok, check the pipes and fuel filter, is the filter new and ok (I have seen them that old that the side rots out on them!).
Now you know the real reason why the consumption was bad.....its pissing it ll over the road
Hi Mark,
Filter and it's connections checked - all bone dry.
It's coming down from the top of the tank, and seems to be running down the back.
Appears to be a fuel spray everywhere in that area.
Any pipes in that region? Guessing tank needs to come off!!! ?
Mark, do you think the exhaust blockage and fuel leak are unrelated?
Edit - just to add to the chaps above - the connections at manifold cannot be wrong, as one is 17mm, one is 19mm, for that reason :y
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'Kin Ell James........four wheel grenade??
PO MUST have known all about this.........??
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Is it possible that the fuel leak and the exhaust blockage are related? As has been pointed out the back pressure has to be immense and will need to vent somewhere... Could it be pressurising the fuel return pipe, perhaps rupturing that?
Can't see how pressure in the exhaust would be able to make its' way to the fuel tank. :-/
Has to be a fuel leak between tank and fuel rail, IMHO.
Get it idling and give the whole length of the fuel plumbing a good waggle. I suspect there's a leak which only opens up when stressed in one particular direction.
No need to drop tank, IMHO. If it's spraying out as you say, it can only be from the connections at the top plate of the tank or the plumbing between there and the fuel rail. All accessible with tank in-situ.
Does make me wonder if the high pressure line from the pump is leaking under the fuel tank top plate as this is the only thing I can think of that might have been responsible for the fuel mist in the tank.
Kevin
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'Kin Ell James........four wheel grenade??
PO MUST have known all about this.........??
Possibly mate, but it's by the by really..... just need to get it sorted :y
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Is it possible that the fuel leak and the exhaust blockage are related? As has been pointed out the back pressure has to be immense and will need to vent somewhere... Could it be pressurising the fuel return pipe, perhaps rupturing that?
Can't see how pressure in the exhaust would be able to make its' way to the fuel tank. :-/
Has to be a fuel leak between tank and fuel rail, IMHO.
Get it idling and give the whole length of the fuel plumbing a good waggle. I suspect there's a leak which only opens up when stressed in one particular direction.
No need to drop tank, IMHO. If it's spraying out as you say, it can only be from the connections at the top plate of the tank or the plumbing between there and the fuel rail. All accessible with tank in-situ.
Does make me wonder if the high pressure line from the pump is leaking under the fuel tank top plate as this is the only thing I can think of that might have been responsible for the fuel mist in the tank.
Kevin
Just a thought but
Do the fuel pressure regulators ever fail?
Could a failed or blocked (or tampered with) fuel regulator be causing a ridiculously high pressure in the fuel line leading to excessive fuel consumption and leaks in the fuel lines?
Is there a test connection on the fuel rail for a pressure gauge?
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Just a thought but
Do the fuel pressure regulators ever fail?
Not common but not impossible. :y
Could a failed or blocked (or tampered with) fuel regulator be causing a ridiculously high pressure in the fuel line leading to excessive fuel consumption and leaks in the fuel lines?
I wouldn't expect the engine to run normally, and I would expect the plumbing to stand up to the highest pressure the pump can deliver but it's possible.
Is there a test connection on the fuel rail for a pressure gauge?
Yes, there's a schrader type valve at the rear of the fuel rail.
Kevin
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Hi Kev,
I still think the tank may actually need to come off :-/
Thing is, with it idling, even when you can see fuel piddling on the ground, the inspection area in the boot is bone dry.
It seems to be running down the very rear of the tank, bumper side, from the top. There is some sort of pipe up there too, can’t see what it is, though… :(
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I wouldn't expect the engine to run normally, and I would expect the plumbing to stand up to the highest pressure the pump can deliver but it's possible.
Is it running normally :-/
I'm half convinced by the theory about a spray or jet of petrol inside the tank(maybe as a result of excessive pressure) finding a weak point in a tank seal somewhere.
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James, I had a simular problem on my old facelift, it tuned out to be that someone had cross threaded the big plastic ring that holds the plate to the top of the tank, it only started leaking when pressure had built up, bone dry when not running.
HTH :y
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It's all bone dry around the ring..
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Time to see the doctor when you have a leaking ring.........LOL!
(and I'm not talking from experience!!)
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Time to see the doctor when you have a leaking ring.........LOL!
(and I'm not talking from experience!!)
trust you..... ;D
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Sorry James, just trying to lighten the mood a bit.............
having a bitchin' time doing the wishbones, drop links and idler myself this morning, 4 out of 10 knuckles skinned so far........
better than you, though. Sorry I can't say anything really constructive and helpful!
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you do buy some right lemons don't you ;D
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you do buy some right lemons don't you ;D
break off ;D
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Hi Kev,
I still think the tank may actually need to come off :-/
Thing is, with it idling, even when you can see fuel piddling on the ground, the inspection area in the boot is bone dry.
It seems to be running down the very rear of the tank, bumper side, from the top. There is some sort of pipe up there too, can’t see what it is, though… :(
Only places where it should be able to leak are in the inspection area (pipes go forward from here, so leak unlikely to be evident from the rear of the tank) and where the filler enters the tank. Might be a breather pipe or something there that has chafed through, or a hole in the tank, I suppose. :-/
Might well be worth dropping the tank for a look, if only so you can be 100% sure you've nailed it. You know the drill after Marie's LPG conversion. ;)
EDIT: I would say pull the fuel pump plate off and check the plumbing under it while you're at it, as I'm thinking something is spraying fuel around under there.
Kevin
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you do buy some right lemons don't you ;D
break off ;D
Its about the only thing useful i could add to this discussion ;D
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Indeed, I know the score.
Maybe I should just leave it off, and put an LPG one in it's place :-X
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EDIT: I would say pull the fuel pump plate off and check the plumbing under it while you're at it, as I'm thinking something is spraying fuel around under there.
Kevin
If this is the plate in the boot, I've taken it off. All bone dry, even when fuel is dripping down the back onto the floor...
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EDIT: I would say pull the fuel pump plate off and check the plumbing under it while you're at it, as I'm thinking something is spraying fuel around under there.
Kevin
If this is the plate in the boot, I've taken it off. All bone dry, even when fuel is dripping down the back onto the floor...
I meant the plate under that through which the fuel lines and electrical connections exit the tank. :y
Kevin
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EDIT: I would say pull the fuel pump plate off and check the plumbing under it while you're at it, as I'm thinking something is spraying fuel around under there.
Kevin
If this is the plate in the boot, I've taken it off. All bone dry, even when fuel is dripping down the back onto the floor...
I meant the plate under that through which the fuel lines and electrical connections exit the tank. :y
Kevin
Ah ok. So, unscrew the big ring? :y
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sorry, only just come to this....
glowing cats have two causes :-
first is a lean mixture, usually an inlet air leak, resulting in over-hot exhaust gas.
second is a large amount of unburnt fuel hitting an already-hot cat. obviously my favourite for this.
for that kind of fuel usage, you are probably beyond the damage that a bust lambda sensor could do, but you'll already need two new ones anyway.
I'd look at the fuel pressure regulator - it is possible for the diaphragm to burst, allowing pressurised fuel directly into the inlet manifold - that'd cause your problem.
next, look at lambda failure + coolant temp sensor failure, but this should be obvious from the datalog in the Motronic ECU.
regarding the fuel tank vent - there is only one and it's in the evap loss can under the wing - the rest of the system is sealed. With the engine OFF, the tank and the evap loss can are connected, allowing the vapour raised through heating the fuel in the tank on a hot day to be collected in the canister. With the engine ON, the putrge valve opens occasionally to allow the stored vapours to be drawn into the engine. ( it's the one above the breather box ). I would double check that the fuel tank is under pressure and not under vacuum. reason being that there isn't a ready source of pressure available to do this. Certainly fuel pressure couldn't cause a tank to become pressurised.
so, in conclusion....
replace the exhaust and all the lambda sensors.
check the fuel pressure regulator
check that all the sensors and vacuum lines are properly connected
make sure that the DIS pack is connected properly
check the fuel tank for splits / leaks
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sorry, only just come to this....
glowing cats have two causes :-
first is a lean mixture, usually an inlet air leak, resulting in over-hot exhaust gas.
second is a large amount of unburnt fuel hitting an already-hot cat. obviously my favourite for this.
for that kind of fuel usage, you are probably beyond the damage that a bust lambda sensor could do, but you'll already need two new ones anyway.
I'd look at the fuel pressure regulator - it is possible for the diaphragm to burst, allowing pressurised fuel directly into the inlet manifold - that'd cause your problem.
next, look at lambda failure + coolant temp sensor failure, but this should be obvious from the datalog in the Motronic ECU.
regarding the fuel tank vent - there is only one and it's in the evap loss can under the wing - the rest of the system is sealed. With the engine OFF, the tank and the evap loss can are connected, allowing the vapour raised through heating the fuel in the tank on a hot day to be collected in the canister. With the engine ON, the putrge valve opens occasionally to allow the stored vapours to be drawn into the engine. ( it's the one above the breather box ). I would double check that the fuel tank is under pressure and not under vacuum. reason being that there isn't a ready source of pressure available to do this. Certainly fuel pressure couldn't cause a tank to become pressurised.
so, in conclusion....
replace the exhaust and all the lambda sensors.
check the fuel pressure regulator
check that all the sensors and vacuum lines are properly connected
make sure that the DIS pack is connected properly
check the fuel tank for splits / leaks
Thanks for your detailed input mate.
In summary - misfire has been sorted with new DIS, plugs and leads.
Cats and exhaust are on order.
Only major problem now is the fuel leak at the tank end :y
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right - O
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Well, the cause of the leak has been identified.
I removed the fuel tank tonight.
At the rear, where the exhaust runs alongside the fuel tank, a great big gaping hole has been melted into the tank. I can get my fist in there!
Wanted - Fuel tank ;D ;D ;D
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mystery solved.... :y
hole caused by heat, caused by misfire?
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Lucky you and your Omega didnt end up going in to orbit. :o :o..........can just picture the scene - "Easyjet flight 345 to ATC, Im sure I just saw the remains of an old Vauxhall Omega flying past, with its arse end on fire". :o :D ;D
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mystery solved.... :y
hole caused by heat, caused by misfire?
Probably, with the unburnt fuel... I reckon it's been going for a while, and just finally let go on the trip home...
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On the upshot, this is an ideal time for fitting LPG rear end, with the tank out :D
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Lost track now, is this an estate?
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Lost track now, is this an estate?
Yup
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Shame, just took the fuel lines off the Golden Nugget (TB's Elite) tonight, the tank is obviously fine but the car is a saloon.
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Shame, just took the fuel lines off the Golden Nugget (TB's Elite) tonight, the tank is obviously fine but the car is a saloon.
I'm correct in thinking, Saloon tank is different?
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Yep, Estate tank has to deal with the spare wheel well.
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Has it had a new tank fitted, are the returns and vent pipes blocked or incorectly fitted.
Not that I know of.... doesn't look new. :-/
Be tempted to at least check the whole return system, sounds like you are driving an armed bomb arround. :-/
Not too far off the mark then. :-/
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mystery solved.... :y
hole caused by heat, caused by misfire?
Probably, with the unburnt fuel... I reckon it's been going for a while, and just finally let go on the trip home...
I don't suppose there was supposed to be a heat shield between the exhaust and tank? I'm struggling to imagine how hot the exhaust must have got. :-/
Kevin
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Well there is on the petrol saloons so I'm guessing an estate would be much the same.
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mystery solved.... :y
hole caused by heat, caused by misfire?
Probably, with the unburnt fuel... I reckon it's been going for a while, and just finally let go on the trip home...
I don't suppose there was supposed to be a heat shield between the exhaust and tank? I'm struggling to imagine how hot the exhaust must have got. :-/
Kevin
There was a heat shield. It was around one of the heatshield bolt areas on the tank that the hold is ;D
I agree Kev, seems unlikely - but what else! It's visibly melted, rather than split... :-/
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mystery solved.... :y
hole caused by heat, caused by misfire?
Probably, with the unburnt fuel... I reckon it's been going for a while, and just finally let go on the trip home...
I don't suppose there was supposed to be a heat shield between the exhaust and tank? I'm struggling to imagine how hot the exhaust must have got. :-/
Kevin
There was a heat shield. It was around one of the heatshield bolt areas on the tank that the hold is ;D
I agree Kev, seems unlikely - but what else! It's visibly melted, rather than split... :-/
HAV E seen this twice before!! on one it was a split along the sea,m of the rear box the other was a rust hole, hot gases from the split/hole had very gently over time melted the fuel tank!!!
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I managed to melt the outside of a hi-viz jacket in the boot of the jag with the same issue - exhaust from a holed back-box directly heating the floor.
have killed a few cats in my time, mainly on prototype and test vehicles. I distinctly remember causing a huge tailback on the M25 after melting four cats in a Lamborghini. Got billed for re-surfacing, too.
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mystery solved.... :y
hole caused by heat, caused by misfire?
Probably, with the unburnt fuel... I reckon it's been going for a while, and just finally let go on the trip home...
I don't suppose there was supposed to be a heat shield between the exhaust and tank? I'm struggling to imagine how hot the exhaust must have got. :-/
Kevin
There was a heat shield. It was around one of the heatshield bolt areas on the tank that the hold is ;D
I agree Kev, seems unlikely - but what else! It's visibly melted, rather than split... :-/
HAV E seen this twice before!! on one it was a split along the sea,m of the rear box the other was a rust hole, hot gases from the split/hole had very gently over time melted the fuel tank!!!
Bingo!!! There IS a split in the backbox, directly facing the fuel tank!!! :y
New exhaust on order... :y
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Hi James, congratulations not only on solving your problem(s), but for escaping what surely could have been a fiery disaster! It would probably be difficult to claim much against the seller, as the tank hole may have only occurred on your drive South.
Best of luck with the reconstruction, and full marks to all the expert advice on here.
Chris :y :y :y
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Hi James, congratulations not only on solving your problem(s), but for escaping what surely could have been a fiery disaster! It would probably be difficult to claim much against the seller, as the tank hole may have only occurred on your drive South.
Best of luck with the reconstruction, and full marks to all the expert advice on here.
Chris :y :y :y
Amen to that. That explains where all that fuel vapour came from when you filled up. Boiling petrol. :o One spark away from something rather nasty.
Anyway, given that the fuel tank is now U/S this makes this estate the ideal test bed for fitting a reduced size petrol tank, chopping out the spare wheel well and fitting a huge underslung LPG tank. ;)
At least with 8 BAR of pressure in the fuel tank it's less easy to drive around oblivious to a hole in the tank. ;)
Kevin
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I was looking at this last night... and I was thinking the LPG tank would be too close to the exhaust for comfort, if it was slung under the boot floor..... :-/
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Hi James, congratulations not only on solving your problem(s), but for escaping what surely could have been a fiery disaster! It would probably be difficult to claim much against the seller, as the tank hole may have only occurred on your drive South.
Best of luck with the reconstruction, and full marks to all the expert advice on here.
Chris :y :y :y
Amen to that. That explains where all that fuel vapour came from when you filled up. Boiling petrol. :o One spark away from something rather nasty.
Anyway, given that the fuel tank is now U/S this makes this estate the ideal test bed for fitting a reduced size petrol tank, chopping out the spare wheel well and fitting a huge underslung LPG tank. ;)
At least with 8 BAR of pressure in the fuel tank it's less easy to drive around oblivious to a hole in the tank. ;)
Kevin
I liked my old Jag and Daimler, they had a 10 gallon tank on each side of the car, also would be ideal for trying 2 types of petrol at the same time and same road/weather conditions if they were fitted to a miggy.
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I was looking at this last night... and I was thinking the LPG tank would be too close to the exhaust for comfort, if it was slung under the boot floor..... :-/
Would it fit under the boot floor, and being nearer a heat sourse with a presurised tank is that really a good idea.
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I was looking at this last night... and I was thinking the LPG tank would be too close to the exhaust for comfort, if it was slung under the boot floor..... :-/
It would, no doubt need to be protected from the heat with a shield.
Another option. Cut out the wheel well and extend it deeper so tank is still enclosed in the wheel well.
Kevin
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'Kin Ell James........four wheel grenade??
PO MUST have known all about this.........??
Seems I was closer to the truth than I thought.............
The P.O. must be told........surely that was just plain dangerous, selling it in that state??
maybe there is a law against selling a car that potentially could explode??
Glad you are over the worst, James.
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I haven't read right through yet but the story reminds me of when I bought a 2.5 Elite estate off eBay, located in Staines, 320 miles away. The vendor assured me that the car would drive to Penzance. Well, when I arrived to pick the car up, it was running on 4, maybe 5 cylinders. I was furious. Had I not been so mild-mannered I could have socked the guy. I tried a mad gamble to drive back but it couldn't even stutter to the M4, never mind Penzance. I took the train back (3 changes) and arranged for a recovery guy to pick the car up. Cost me £700 overall. I suppose I should have left it there and demanded my money back. One day I might get my money back in spare parts....
How people can be such barefaced liars is beyond me.
On the upside most of my other eBay purchases have turned out just fine, so I remain the eternal optimist and just regard it as the one of risks of the trade I'm in. ::)
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I think alot of Ebayers rely on the fact you have travelled a long way to collect the car so your not going to walk away. I got the train to Measteg to be met at the train station the seller driving my new purchase. It was a glorious sunny day and the bloke had the heater on full blast and the window down. When I got in to drive off and turned the heater off the temp gauge started to rise so I had to drive home with the heater on >:(
Still car turned out fine once I had flushed the rad, turns out the oil cooler had let go which he'd had replaced but not flushed the cooling system well enough :)
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Im glad it all got sorted in the end, :) BUT i am going to miss my daily episode of "a very poorly Elite" :'(
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Im glad it all got sorted in the end, :) BUT i am going to miss my daily episode of "a very poorly Elite" :'(
Oh I've no doubt there is more to come!! ;D
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Just caught up with this thread.
I should be preparing to lay a patio not sitting here reading about problem Omegas.
Glad it's sorted though, good read and resolution :y
Mick ;)
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You should have a section of your own James - 'what f****d up on me today' ;D
Jon
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Ahhhh maybe... but.... it will all be super duper once fixed, and LPG'd ... ;)
The car is actually very tidy indeed, so it's well worth doing.
I have 2 x new cats, and a cat back eternal car exhaust system on the way, so she'll even be able to breathe again, when back together :y
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Are you fitting a fire extinguisher system. ::) Sorry :-[