Hi there,

 

wondering if someone can advise me so I’ve just picked my car up today from having the intake manifold changed and the fuel injectors changed all 4.

 

the car is still missfiring and revving on it’s own the garage have done a compression test and everything comes back as correct. But can’t work out why it would be misfiring and revving on it’s own please can someone advise I’ve check the pvc and this seems to be working fine it’s throwing up no codes at all apart from no4 misfiring had new spark plugs also and swapped the ignition coils around.

 

£500 later and it’s still not fixed please advise 😢

Was the car doing this before the manifold and injectors where changed? Maybe worth checking the pipe on the front of the pcv is correctly connected, I had my injectors done and one the way home it started misfiring with erratic idle, when I checked the pipe at the front from the inlet to the pcv it was disconnected, as it’s a bit of a dodgy plastic clip fitting I think it must have not been fully pushed on and had worked loose with the vibrations driving 

Hi thanks for your reply the car idled fine and had no misfire before the intake manifold only when the old actuator arm popped out as this is a known fault I have checked the pipes like you suggested and everything seems to be plugged as it should be any more idea much appreciated!

2 hours ago, maximusvrs said:

Was the car doing this before the manifold and injectors where changed? Maybe worth checking the pipe on the front of the pcv is correctly connected, I had my injectors done and one the way home it started misfiring with erratic idle, when I checked the pipe at the front from the inlet to the pcv it was disconnected, as it’s a bit of a dodgy plastic clip fitting I think it must have not been fully pushed on and had worked loose with the vibrations driving 

thanks for your reply the car idled fine and had no misfire before the intake manifold only when the old actuator arm popped out as this is a known fault I have checked the pipes like you suggested and everything seems to be plugged as it should be any more idea much appreciated!

Has it been scanned with Vag Com?

Only thing I can think of that would make it rev on its own would be the throttle body opening of its own accord, cant see how that would cause a "misfire" though, mine hunted at idle sometimes when it had a throttle body issue, dropping below idle and then creeping back up again...

3 hours ago, brown_d9 said:

Has it been scanned with Vag Com?

Only thing I can think of that would make it rev on its own would be the throttle body opening of its own accord, cant see how that would cause a "misfire" though, mine hunted at idle sometimes when it had a throttle body issue, dropping below idle and then creeping back up again...

Yes the car has been scanned by Vagcom there are no fault showing at all throttle body position is show as correct it’s just once you watch each cylinder 123 are all sat at zero and cylinder 4 climbs Upto 130 but all had brand new injectors yesterday 

When you say you are watching cyclinder 1,2,3 read 0 and #4 climbing to 130, do you mean the Vag com mis-fire counter?

3 minutes ago, brown_d9 said:

When you say you are watching cyclinder 1,2,3 read 0 and #4 climbing to 130, do you mean the Vag com mis-fire counter?

Yes that is correct watching the vag com misfire counter 

Hmmm odd one, sounds like it must be a faulty new injector?

6 hours ago, brown_d9 said:

Hmmm odd one, sounds like it must be a faulty new injector?

Had the car back down at the garage today checked all the compression in each cylinder came back as correct checked all the sparks suspected pvc failure got this part being changed tomorrow. Intake manifold also threw up code again so possibly suspect fault intake but try the pvc tomorrow see if this fixes the problem if not any more suggestions 🤣