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[Kevin Wood]

we did use the lpg loom plugs, just plug and play in theory. The length of the loom wires to plugs means its difficult to get the plugs wrong and not notice

 

I can testify to the fact that swapping the cables over for the petrol injectors doesn't noticeably affect running, although swapping them across banks obviously will screw up the Lambda loops (actually, it had the side effect of extinguishing the emissions light on my 3.2, for some bizarre reason.

A "stuck on" injector will obviously cause serious issues, though.

Kevin

[Jimbob]

Its somewhat comforting to see I am not the only oof'er to become stranded when a job doesn't go exactly to plan

[2woody]

I have an engine that's just spat out a big end. It sounded the same as this. Actually, it sounded just like a stuck lifter......

you can check easily. If you get the offending cylinder to TDC and rock it to and fro, a screwdriver down the plug hole will reveal any play that could be in the bearing.

Kevin, I was going to ask if I could pop by on thursay evening to talk MS with you. ( I'm in the South on thursday & friday ) we could have a chat over the car if you like - and if the owner is willing.

I'll come with tools and prepared for a head-removal, too. Can certainly get it stripped and the head off in an evening

just re-read this - where is the car currently ?

[Kevin Wood]

I have an engine that's just spat out a big end. It sounded the same as this. Actually, it sounded just like a stuck lifter......

you can check easily. If you get the offending cylinder to TDC and rock it to and fro, a screwdriver down the plug hole will reveal any play that could be in the bearing.

Kevin, I was going to ask if I could pop by on thursay evening to talk MS with you. ( I'm in the South on thursday & friday ) we could have a chat over the car if you like - and if the owner is willing.

I'll come with tools and prepared for a head-removal, too. Can certainly get it stripped and the head off in an evening

just re-read this - where is the car currently ?

The car is with me in Four Marks.

I'd be happy to have a chat about Megasquirt, and should be around on Thursday. 

I am hopeful that a check of the injector wiring might reveal something. I think it's highly unlikely that it's a big end but thanks for the tip anyway. Can't hurt to try it.

My comment about the big end was that if someone brought a car to me making those sort of noises without knowing the history that would be my first thought.

In this case, the car apparently enjoyed some spirited driving on the way over and sounded sweet enough when it was pulled into my garage. Unlikely for a big end to simply fail at start-up when it had previously been fine under load IMHO. Something caused by / related to the LPG install would be more likely.

Thanks for the offer of help. Let's see how it goes. Ultimately it's TheBoy's car so up to him what steps are taken to resolve it.

Kevin

[TheBoy]

we did use the lpg loom plugs, just plug and play in theory. The length of the loom wires to plugs means its difficult to get the plugs wrong and not notice

 

I can testify to the fact that swapping the cables over for the petrol injectors doesn't noticeably affect running, although swapping them across banks obviously will screw up the Lambda loops (actually, it had the side effect of extinguishing the emissions light on my 3.2, for some bizarre reason.

A "stuck on" injector will obviously cause serious issues, though.

Kevin

Worth another tech2 on it, see if its poked up any extra pointers.  Fully expect:

19 or 31 (seeing as we have played silly beggers with that sensor)
55 ecu fault (normal on this car)

Just wondering if the playing around the ecu connector has introduced something.  Though the noise does sound mechanical  :-/

[TheBoy]

Its somewhat comforting to see I am not the only oof'er to become stranded when a job doesn't go exactly to plan

I am indebted to Mr Wood for ensuring I wasn't stranded, and I made it back for work this morning. 

Talk about real friendship

[2woody]

ok so I'll come over on thursday, just pm me your postcode - you'll be able to tell when I'm outside your place 

would be pleased to pitch in with the spanners if needs be.

the engine in mine originally failed in exactly the same manner. started up to reveal the noise. Everyone but everyone thought it was a follower, to the extent that I changed all of the followers, but it was only the screwdriver test that revealed the bearing issue.

there were a couple of O-rings blocking the oil pump pick-up. Strangely enough, the rest of the engine is as clean as a whistle - none of the other bearings are marked, yet one had knocked-out to the extent that it had spun. A clean-up and some bearings have taken away 90% of the knocking, but I'm wanting to change the rod before I give it porper usage.

[Marks DTM Calib]

When are you removing the LPG setup from the equation Kevin?.

As many know, I dont prescribe to conincidental faults.....hence, at this stage, it needs to be infered that the fault is a consequence of the work done/bits added.

And, as we all know, just because something is new, does not guarantee that it works.

[TheBoy]

When are you removing the LPG setup from the equation Kevin?.

As many know, I dont prescribe to conincidental faults.....hence, at this stage, it needs to be infered that the fault is a consequence of the work done/bits added.

And, as we all know, just because something is new, does not guarantee that it works.

Exactly.  I don't think its bigends, purely because there is nothing we have done that could have affected them.  It has to be something around what we have done, which currently points to the LPG causing it, something dropped down the inlet, or an error in reassembly of intake/plenum (unlikely I would say, did most of it myself)

[Marks DTM Calib]

When are you removing the LPG setup from the equation Kevin?.

As many know, I dont prescribe to conincidental faults.....hence, at this stage, it needs to be infered that the fault is a consequence of the work done/bits added.

And, as we all know, just because something is new, does not guarantee that it works.

Exactly.  I don't think its bigends, purely because there is nothing we have done that could have affected them.  It has to be something around what we have done, which currently points to the LPG causing it, something dropped down the inlet, or an error in reassembly of intake/plenum (unlikely I would say, did most of it myself)

Exactly, hence why the first thing to do is get back to the last known point that it was working. 

[2woody]

I might just be able to borrow a "snake-eye" for the day, will let you know.

[Entwood]

It's not something as simple as the LPG injectors/pipes/clips rattling against the underside of the pleneum??

Is it worth disconnecting all the lpg gas lines & electric lines and running it on petrol just to see if the fault remains ??

[Kevin Wood]

I'm not suggesting it's the big ends. I have stated that it's impossibly unlikely that they would just happen to fail on startup after unrelated work, and after previously being fine under load. I merely commented that the noise sounded of a similar level of "seriousness".

I agree that the LPG setup and particularly a stuck open injector are under suspicion. These are things we had overlooked in the limited diagnosis we performed last night so as soon as I feel awake enough they will be the first items to be eliminated.

EDIT: Our first thoughts were that it could be a new component rattling, especially as the injector bracket is not well supported. Another listen proved beyond doubt that this was not the case.

Kevin

[Marks DTM Calib]

On the plus side, if a foreign object had got into the inlet and caused valve damage, I would expect close to a 0 compression reading.....

[Kevin Wood]

On the plus side, if a foreign object had got into the inlet and caused valve damage, I would expect close to a 0 compression reading.....

Agreed. It isn't going to raise 6 bar during cranking with any damage to speak of.

I'm also sure we would have seen witness marks on the spark plug and piston crown if that were the case.

I will try the fluid on the intake valve check and the light behind the valve check as it's stripped down, then eliminate all the LPG electrical stuff and put it back together. I can even put on a spare manifold without any nozzles, thinking about it.

Kevin