A4 B6 2.5TDI Quattro idle issues???

[elzzup]

Hi,
so iv'e had my A4 for about 3 months now and i love it!!!! i took it for a health check courtesy of Audi and the usual crap returned, replacement screw £140, wiper linkage squeaking £245vyada yada, anyways one of the things found was the G80 injector had an intermittent fault....

there was a slight stutter in the idling which id noticed but only when at stop and when you really tried to feel it as it doesn't show on the rev counter but it is noticeable....

so without further hesitation i plugged her in myself and sure enough G80 intermittent short to plus or open circuit.
bought the injector, £350 worse off replaced it and the code went away... YAY success...

however this did not remove the funky idle!!!! there are no more fault codes after a clean sweep with vag-com but still this random lumpy but hardly noticeable idle lumpyness!!!! and its driving me mad.

anyone had an issue like this before? the car runs fine otherwise.... good mpg around 37 average, smooth motorway running and a dream to drive!

2001 A4 2.5 TDI Quattro AKE with 99K genuine!
cam belt at 80K

Regards to anyone who has any ideas!!!

Niki

 

[quattrojames]

Hi Niki and welcome to the forum.

It could be anything, but assuming a VCDS scan shows nothing then there's always the possibility it's a fuel pump VP44 error...

 

[white.akita]

Maf doesnt always show fault code.

 

[Tarmons]

One of the injectors has a needle lift sensor, drivers side, closest one to the windscreen (if I remember correctly). You will see a wire coming from it, worth checking that the wiring is ok as I believe the wire is sandwiched between the rocker cover and head (no special path for it).

Afaik this injector cannot be refurbished so you will need a new one (if no wiring fault found), they are not cheap from audi but find the bosch part number and you may find it cheaper.

See thread:
http://www.audi-sport.net/vb/vcds-formerly-vag-com-forum/17540-00542-needle-lift-sensor-g80.html

 

[elzzup]

Hi,
yeah i replaced the G80 as stated at £350 squids to no avail! i will get a new MAF anyways and see if it makes a difference.
Regards

 

[swarcup]

dual mass flywheel could be a culprit, these 2.5tdi's do use them up, do you suffer a judder on take off or changing gear when its warm and had a run out?

 

[elzzup]

Hi,
i had considered the dual but there are no other signs! it pulls great on all gears and doesn't judder or lurch at all....

 

[Tarmons]

Sorry I did not read your original post carefully enough, with regards to the sensor injector.

I believe you can just disconnect the MAF and see it if improves the idle before putting your hand in your pocket again.