Very Weird Idling... Help

[Stevoo]

hey guys, i have a 1997 r plate 2.3 auto. I started having an idle issue 2 weeks ago ONLY when car temp got warm. it would idle un and down when stationary and sound like engine is missing a beat but not miss fire.

 

had a full service new plugs oil etc, needed new Coil packs as garage thought that caused the idle issue.

 

Now car idles badly from cold start till warm finish. it hasnt stalled but is a pain. car drives well and no performance probs at all.

When i engage drive at times the revs naturally drop a wee bit, but now it drops to 800 ish and car bunny hops when foot on brake. like its trying to stall but revs up etc.

 

Any ideas?? sounds like idle contral valve to me? do i have one?

 

Ive tried card cleaner in intake and stp fuel cleaner.

[big_kev]

Possible dodgy fuel....you didn't fill up at Tesco or Morrisons 2 weeks ago

 

Heard that this can trash some of the sensors.

[fionnmacz]

this sounds like my prob last year with my petrol sharan. I changed the air temp sensor, there were apparently a bad batch of them in late 90's , and the prob was resolved. runs perfectly now. maybe you should have yours checked.......may be - may be not the prob.........

[charles]

I have had similar problems, see older threads

you should check or just replace the following items

MAF sensor, lamda sensor, carefully check wiring (broken isolation) and connections

exaust gas recirculation valve (stuck)

[charles]

o yeh, forgotten, clean your idle air valve

[Stevoo]

Thanks for replies, had car in garage, and found a split air pipe for crank vent.

 

I have cleaned all sensors and given car a good run out on motorway and now running sweet as. so glad it wasnt MAF :-)