Intermittent revs? 2.9i

[NeilS3]

S3 2.9i pulls well and does the things it should while out driving, however recently on tick over (especially on start up) will change revs while stationary and sometimes the engine will almost try and cut out due to low tick over.

Anyone shed some light on this, always greatly appreciated.

Thanks

Neil

[Gerald-TVR]

Air leak in the induction????

[Barkychoc]

or a sticking idle valve thingmebob?

[Sandgrounder]

Sounds a similar issue to my own S3 Neil. Mine now drives reasonably well, but the idle is still a bit naff. I have had everything checked (except the injectors), and just put it down to the fact that the engine is old.

[Harry1972M]

Throttle potentiometer ??? try unplugging it and re start it should tick over much higher but if it is steady then this could be an indication it's duff.
I also had an odd one when I had mine in that the brake servo had rusted through causing an air leak to the plenum (if I remember correctly) I only found this as I noticed a change in revs when stationary if I pressed the brake pedal.

[NeilS3]

Thanks a lot guys for your help,

Turns out, after a few burnt fingers, found a small leak tucked away on the underneath the n/s exhaust manifold, small amount of exhaust gasket blowing which is now neatly sealed.

Cheers Guys.