Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: omegod on 05 November 2010, 10:52:48
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I fitted a 2nd( Gen VX this time) new Crank sensor this morning after pinning my hopes on this being the cause of my non start problems which go as follows:
Was not starting 9 times out of ten so I fitted a pattern part, it then would start but ran like a bag of crap. Then decided not to start at all. Fitted the new sensor this morning and it still will not start. RAC are here at the moment and the spark appears ok and the guy is mystified.
It is LPG converterd and would normally start on either and despite my protest he squirted a shit load of eazystart in it to no avail.
Does anyone have an idea what to check/change next? Could this be another sensor? Elecrtical problem? no codes stored btw.
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Is the fuel pump firing up to pressurise the system? Try removing and reseating the fuel pump relay and check the fuse to ;)
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Guy has messed about with the fuel pump fuse and it has no live feed, he can get it to start on gas with a direct feed but it runs like crap, this appears to be an immobiliser problem , can this be bypassed in any way?
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Immobiliser's can be by passed but not the sort of thing that is discussed on open forums (ive no idea how) but the guys with the remote starts may be able to advise.
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Any tips by pm then please ;)
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I genuinely have no idea but sure some one will help you out :)
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RAC diagnosis is " fuel pump relay lost earth to pin 85 - ecu, checked wiring continuity of wiring to ecu ,ok, suspect either ecu fault or gas ecu fault"
This is a real pain in the ass, does this rule out Dis pack, immobiliser I wonder?
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Is the fuel pump firing up to pressurise the system? Try removing and reseating the fuel pump relay and check the fuse to ;)
The spark has been checked so the use of EazyStart would cause the engine to run if it were a fuel problem...
Guy has messed about with the fuel pump fuse and it has no live feed, he can get it to start on gas with a direct feed but it runs like crap, this appears to be an immobiliser problem , can this be bypassed in any way?
Immobilizer issues usually cause the e.m.l. to flash when the ignition is first switched on...
Does your e.m.l. light come on at all when you try and start the car? Is it flashing?
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Omegod - Assuming this is a V6 -
The crank sensor fitted in the factory, is routed up behind the oil cooler pipes, into the engine bay.
When the original sensor fails and a mechanic replaces it, often he/she will simply cut off the old sensor, leaving the old wire in place, (because it's too difficult to remove) and fit an additional new one.
If this has happened on your car, you could well have a redundant crank sensor plug in your engine bay, that you are connecting up to the loom, in the belief it's the crank sensor - when in fact, the new sensor is actually not plugged into anything at all.
(Although, if you have a spark on all the plugs, this is unlikely).
Not teaching you to suck eggs, but this one foxed me once before, and I never forget it! :)
Aside of this -
* Are the plugs wet?
* Are there any ECU codes stored?
* Is there any pressure in the fuel rail?
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Definately the new sensor plugged in, wondering if there may be a fault with the connector it goes into though, looks a bit shagged
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RAC diagnosis is " fuel pump relay lost earth to pin 85 - ecu, checked wiring continuity of wiring to ecu ,ok, suspect either ecu fault or gas ecu fault"
This is a real pain in the ass, does this rule out Dis pack, immobiliser I wonder?
Very unlikely.
Gas ECU won't touch the fuel pump feed and the petrol ECU is a very unlikely failure.
The petrol ECU will only activate the fuel pump relay signal if it detects that the engine is cranking, so was it cranking when he tested it?
Pin 85 of the fuel pump relay isn't connected to the ECU anyway, unless I'm mistaken. :-/
A better step would have been to bridge the two contacts of the fuel pump relay and check that the fuel pump runs, then see if it starts.
Do you get a flashing light on the dash when cranking? If so, it indicates immobiliser is still active.
Have you got any trouble codes stored in the engine ECU?
I'm tending to think the crank sensor has something to do with it, as it has caused issues in the past. :-/
Kevin
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Omegod - Assuming this is a V6 -
The crank sensor fitted in the factory, is routed up behind the oil cooler pipes, into the engine bay.
When the original sensor fails and a mechanic replaces it, often he/she will simply cut off the old sensor, leaving the old wire in place, (because it's too difficult to remove) and fit an additional new one.
If this has happened on your car, you could well have a redundant crank sensor plug in your engine bay, that you are connecting up to the loom, in the belief it's the crank sensor - when in fact, the new sensor is actually not plugged into anything at all.
(Although, if you have a spark on all the plugs, this is unlikely).
Not teaching you to suck eggs, but this one foxed me once before, and I never forget it! :)
Aside of this -
* Are the plugs wet? Will check
* Are there any ECU codes stored?No
* Is there any pressure in the fuel rail? How do I check this?
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Couple of ways to check the fuel pressure -
There is a little schrader valve on the back of the rail (with a screw on cap) - you can remove this cap and press something into this, to see if it's holding pressure (do this just after having ignition on / trying to start it)
You could also slacken the unions on the pipes to check, but be VERY careful to take precautions about spraying fuel whatever you do - it kills when it gets in your eyes :y
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Got code 53 but this may be from him messing about? fuel pump relay voltage low?
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I appear to have fuel pressure as some dribbled out when i pressed in the schrader valve, plugs are not wet, I got it running once, lumpily, on gas so I presume I am getting a spark of some sort but sounds like only on 4-5 cylinders.
EML does not flash when cranking, AARRGGHHHHH!!! what the break is wrong with it.
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If the engine is stone cold, it will run very poorly on gas. This is to be expected, because there won't be any heat in the vaporosor to vaporise the gas properly, until it's fully warm.
The fact it starts (albeit rough) on gas, but not petrol, points to a fuel delivery issue.
This therory is supported by the fact that there is only a 'dribble' from the fuel rail - it should be a good spray, under pressure.
Shoot me for asking but, is there enough fuel in the tank?
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Stuck £10 in this morning!
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From a can, presumably?
I reckon, for whatever reason, fuel pump isn't spinning...
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Will get a new relay tomorrow and try that, otherwise I dont have a clue what else it could be :(
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As per Kevin's post - bridge the contacts, and see if the fuel pump runs?
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Mine had the cranksensor go, which was replaced after a week of misbehaving. 2 weeks later, the fuel pump packed up. >:(
Try banging the tank from underneath with a lump of wood or a rubber timmy, then try and start it, pump may be on its way out and sticking :-/
Pump is easy enough to change, and reasonably priced too, iirc :y