MK5 Golf GTI
All Things Mk5 => How to Guides / Troubleshooting => Topic started by: john a on November 26, 2012, 08:09:20 pm
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VCDS tells me I have an intermittent misfire on cylinder 3, this only seems to happen at just over 5100rpm.
I'm assuming the coil is knackered, I need to remove and inspect the plug after I come back from hols, but wanted to know if this was common? I would have thought a misfire could occur at any RPM? Am I way off the mark?
Cheers
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Before you do anything, can we have some more information - is the car mapped at all?
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Move the coil pack to cylinder 1 and clear codes, if the code jumps to cylinder 1 then it'll likely to be the coilack at fault :happy2:
If not, swap just the spark plug and re-test.
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Sorry to jump on this thread. I have a misfire on cylinder 3 at idle (sometimes cylinder 1), despite new plugs & coils. Any ideas PDT??
I've done throttle body adaptation, could the throttle body be dirty? Or maybe an injector?
It's had a 400 mile run this weekend but still does it at idle (doesn't seem to whilst driving)
Cheers
Gray
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Before you do anything, can we have some more information - is the car mapped at all?
Just stage 1 software, and an ITG enclosed Maxogen. The car has only shown the misfire twice - once with a flashing engine light and once without, it's been mapped for a while though and the 2 misfires have only happened recently. Plugs are probably 9k miles old now.
Move the coil pack to cylinder 1 and clear codes, if the code jumps to cylinder 1 then it'll likely to be the coilack at fault :happy2:
If not, swap just the spark plug and re-test.
Stupid question, are cylinders numbered 1-4 L-R or R-L? Ta.
I am also getting an issue with low fuel pressure, again it's under a load in a high gear (only really seems to do this in 4th, maybe 5th). Logs showed a difference between actual and requested, although I have not yet logged low pressure pump and high pressure pump, just rail pressure. I don't know if the two problems are related and will be starting with the fuel filter, followed by the fuel pressure sensor before moving onto the two pumps. Again this is a problem that occurred just before I decided to have the car mapped although it did have another intake (not as free flowing as the ITG either) which made me wonder if the airflow meant the turbo was producing more pressure than the pump could handle, but surely the stock HPFP can deliver enough fuel for a stage 1? Unless it's knackered.
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Cylinder 1 in nearest to the cambelt.
As for your low fuel pressure issue, I would first visually check your cam follower and hope that's is not punched through. :scared:
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I replaced the cam follower about 6k miles ago, so onto chasing other potential probs.
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Sorry to jump on this thread. I have a misfire on cylinder 3 at idle (sometimes cylinder 1), despite new plugs & coils. Any ideas PDT??
I've done throttle body adaptation, could the throttle body be dirty? Or maybe an injector?
It's had a 400 mile run this weekend but still does it at idle (doesn't seem to whilst driving)
Cheers
Gray
Is it definitely a missfire? Does it leave a fault code!
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Sorry to jump on this thread. I have a misfire on cylinder 3 at idle (sometimes cylinder 1), despite new plugs & coils. Any ideas PDT??
I've done throttle body adaptation, could the throttle body be dirty? Or maybe an injector?
It's had a 400 mile run this weekend but still does it at idle (doesn't seem to whilst driving)
Cheers
Gray
Is it definitely a missfire? Does it leave a fault code!
It logs a misfire on VCDS (misfire counter) but doesn't throw up a code or CEL. You can hear the exhaust note change a little and feel a little vibration through the seat when it does it too.
Doesn't seem to do it when the engine is cold, and I find that once it does one, a few more follow not long after :sad1:
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Reset engine adaptions first, then clean the TB and do a tb reset.
At idle its often carbon buildup in the intake ports.
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Cheers PDT, that's the next job :smiley:
Hopefully it might help the intermittant stuttering I'm getting too under load (PM'd you about that a few weeks ago).
Gray