Author Topic: Starting problems  (Read 1287 times)

Offline chargersjoe

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Starting problems
« on: 06 September 2012, 21:09 »
Hi guys,

I have a 1991 8v digi and it was running absolutely fine yesterday on the run home from work, however when I tried to go for a drive last night the car fro no apparent reason wouldn't start. I'm really at a loss here as the engine is getting a spark and smells like fuel is getting to it, especially when looking at the plugs. The fuel pump is priming for a couple seconds when the ignition is switched on. I have just replaced the starter motor as the old one was weak anyway and probably not helping much. All i can think may have caused the problem is if the cambelt has slipped teeth whilst turning the engine over on the cam sprocket, although surely I would have noticed that?

Any help would be highly appreciated.

Thanks guys,
Joe
RIP MK5 1.9TDI

Offline Mr Blue

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Re: Starting problems
« Reply #1 on: 07 September 2012, 18:55 »
I doubt it slipped a tooth. even if it did it would run lumpy. The digi 8v is quite flexible like that.

Wiggle the dizzy plug and have another go.

Wild guess - Ignition moduel ontop of the ECU.
:)

Offline oakgreener

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Re: Starting problems
« Reply #2 on: 08 September 2012, 11:54 »
I doubt it's valve timing out.
It will still run if it's a tooth or two out and if it jumped more than that you would know full well :sad:
Has it got a nice blue spark? A c@ppy yellow one won't do it.

Offline chargersjoe

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Re: Starting problems
« Reply #3 on: 17 September 2012, 17:25 »
Just had the car in my garage, checked all timing marks etc and took the rocker cover off to find that the camshaft was about 40 degrees ahead of the rest of the engine, the exhaust valve on cylinder 4 was fully open as cylinder 4 was at TDC!!! :shocked: I have absolutely no idea how, as it was running fine until i last shut it off  :shocked:

Anyway, I reset all timing marks back to factory marks and she fired up on the first crank, I've now set the timing up with the strobe accurately and she is running more beautifully than ever before  :grin:

Had a good look and no valves are bent or sticking as far as I can see, compression is ok too, I guess these really are non-interference engines after all! :P

If anyone can tell me how this may have happened other than gremlins, poltergheists or fiddly neighbours, I'd love to know!
RIP MK5 1.9TDI

Offline Gambit

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Re: Starting problems
« Reply #4 on: 17 September 2012, 17:50 »
only thing that could have happened is the timing belt has jumped. 8v timing belt tension is roughly 90degree twist on the belt

as you say, 8v is a non-interference engine so you have no issues with bending valves etc - lucky for you!

Offline chargersjoe

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Re: Starting problems
« Reply #5 on: 17 September 2012, 18:25 »
Yeah, I guess it may have slipped as the engine was shutting off, as it kind of jerks as it stops turning? I took the car to a mechanic prior to this happening who loosened the tension slightly as he felt the belt was too tight originally, maybe he didn't secure the tensioner correctly or something, it just seems odd as it ran problem free for a few hundred miles before this happened  :shocked: Oh well, its a mystery, but as long as the car is running and I can go about my daily routine I'm a happy man  :smiley:

Anyways, I have now tensioned the belt up so that I can only just twist it by 90 degrees at the longest point of travel so hopefully all remains good  :smiley:

Yeh I'm really glad they are non-interference at first I was terrified the engine was damaged as some sources say it is an interference engine  :angry:
« Last Edit: 17 September 2012, 18:29 by chargersjoe »
RIP MK5 1.9TDI