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  #1  
Old 13th September 2016, 04:40 PM
ulfilias ulfilias is offline
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Default Misfire ???

Hi There,

I'm trying to get the LPG install working and struggling. On LPG I get a missfire on Cylinder 8.

I know LPG tends to show up faults in cars that petrol is less fussy with and that's what i'm thinking as it's fine on Petrol.

I've changed all the coils and all the spark plugs. I've just swapped coil and pack from 8 (back left) to 5 (front left) with no change at all.

However we've also tried running injector from 8 onto 7 & vica versa which is saying the car, but.....Well what else can cause misfires???

Vagcom codes :

P0300 Random/multiple
P0308 Cyl 8

Any ideas ???


Lee
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  #2  
Old 13th September 2016, 07:40 PM
1781cc 1781cc is offline
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I had this on my B6 S4, cylinder 3 at the time, kept rotating coil packs, no solution - turned out to be the inlet flap - mrc sorted that and the lpg was fine, it was a BRC system
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Last edited by 1781cc; 13th September 2016 at 07:42 PM. Reason: Spellcheck fail
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Old 14th September 2016, 11:47 AM
ulfilias ulfilias is offline
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Hi There,

Interesting. I'm guessing that there is some form of inderviduality within the flap mechanism, which means it can effect just one cylinder.

MRC ???

Thanks,
Lee
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Old 14th September 2016, 12:30 PM
1781cc 1781cc is offline
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MRC are a company based in Banbury, well known for their Audi/VW tuning experience. If you are local they are worth dropping a line, if not, there are similar companies that may help and probably some local to you.
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Old 14th September 2016, 04:39 PM
ulfilias ulfilias is offline
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Hi there,

Peterborough Here....So it's aprox hour and a half drive....Plausible

Though I do like working on it myself!

Lee
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  #6  
Old 22nd September 2016, 08:56 PM
Mechcanico Lee Mechcanico Lee is offline
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If you clear codes and start from cold and switch to gas asap how long does it take before it flags the code , does it have the missfire counter in vcds .
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Old 4th April 2022, 04:37 PM
JG27 JG27 is offline
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Quote:
Originally Posted by 1781cc View Post
MRC are a company based in Banbury, well known for their Audi/VW tuning experience. If you are local they are worth dropping a line, if not, there are similar companies that may help and probably some local to you.
I'm having the same issue with my 2.7T - could you please help what do you meant by "inlet flap"?
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Old 19th April 2022, 01:15 PM
ulfilias ulfilias is offline
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Quote:
Originally Posted by JG27 View Post
I'm having the same issue with my 2.7T - could you please help what do you meant by "inlet flap"?
This "misfire" issue was just how it presented in VAGCOM, mainly on the LPG fuel side of things and caused me to go right through the engine tracking and trying things.

The 4.2 petrol V8 is quite a complex beast and the onboard error stuff is actually pretty basic, so agree with steamship, you'd probably do better elsewhere as this place is great for A8/S8 stuff, but we've not got much experience on other things!
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Old 16th April 2022, 02:56 PM
JG27 JG27 is offline
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Quote:
Originally Posted by 1781cc View Post
I had this on my B6 S4, cylinder 3 at the time, kept rotating coil packs, no solution - turned out to be the inlet flap - mrc sorted that and the lpg was fine, it was a BRC system
what do you mean by inlet flap? i have the same problem
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  #10  
Old 16th April 2022, 04:17 PM
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steamship steamship is offline
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Quote:
Originally Posted by JG27 View Post
what do you mean by inlet flap? i have the same problem
He may be referring to the flaps in the intake manifold.
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