Quote:
Originally Posted by phil200tdi
I just managed to pull a SES light and code:
29D0 Misfirings, cylinder 4
Plugs changed a couple of weeks ago to rectify this - to no avail. I'll try to switch coils with another cylinder and see if the code travels.. if not could be injector or worst case carbon buildup.
Steve, you have a similar mileage to me - have you cleaned the valves yet? Mine just does long runs at motorway speed so hopefully the worst of the carbon is getting burnt away...
|
Ermmm... no.
Too scared LOL!
I think I have pinned my occasional stutter and rough start issue at last.
I too suffered sporadic misfires on cyl3 too, and very rarely a limp.
Swapped over after cleaning, both of the VANOS control solenoids.
No more error coded there or limps, as from the freeze-frame timing the limp was directly linked to VANOS valve on outlet.
However, I always suspected multiple issues and this seems to be the case.
Replacing coilpack (I had a couple of spares on shelf from a member on here) appeared to fix the missing.
But maybe it was only the biggest and most obvious issue, probably on the same cylinder.
Plugs were done by matter of routine a few thousand ago, no change and not replaced for a specific reason other than age.
This last weekend she started really lumpy, smoked a bit and stank of fuel.
A quick blip soon cleared it and it ran fine all week again.
A classic symptom of a sticky injector dribbling fuel into a shutdown engine.
It does this very rarely, normally after a thrash when its shutdown hot and fuel rail pressures will be high.
But, it tells me I have an injector acting up, and its likely cly3 as this is where I got the occasional misfire code.
I may try pulling them and getting them ultrasonically cleaned.
Did this myself in a lab once and it made a massive difference to an old Vauxhall I used to run.
As for carbon....
I read SO MANY threads on this but not one single person can catagorically say it fixed anything.
In fact appart for a little obstruction at high velocity (possibly roughness at small throttles) i fail to see what carbon in the intake will do.
Sure, its the reverse of gas-flowing the intake port, but it wont make 'that' much difference.
Certainly dont see how and oily intake will cause the errors people think it does.
Hey-ho - its all good fun!
I am at 70k or so IIRC.
PS- datalogging the HPFP fuel pressure was quite telling, as I thought this was the root cause of all the rough running and lumpt start.
However the rise of pressure and the actual pressure looks great, its always stable and gets to target quickly and cleanly every shift.
Still feel a slight surging on full bore sometimes, intermittant and never any codes. Must be an injector...
The HPFP job would be an inlet off, so if going to do that then the inlet might as well get cleaned too. Hopefully no need to go there.