JakeS2

Okay, finally the S3 is outta garage and at home

But we have some issues when the engine is warm
1)it refuses to start
2)engine stalls if car does not move & gear is engaged
2)idle dwells a little (sometimes)
3)exhaust smells a bit rich

When the car has just started it performs flawlessly (And is absolutely GREAT to drive!!!!)

So, what could it be ? TPS stuck? ICV (idle control valve) broken?

JakeS2

Okay, answering to myself, suspecting ICV or TPS (the TPS is so cheap I might change it anyway).

JakeS2

And continuing, TPS is changed and ICV cleaned ; and it seems to work ok. Could this be a vacuum leak somewhere? Car idles at 1500 when it starts up but as she warms idle drops to 1000-900 and hovers there...

TT

Have you tried resetting the DME? Just disconnect it for a minute, reconnect, and then see if that changes the behaviour.

Lemming

I'm not clear, is everything fine now?

As for idle, 950 sounds fine after warm up. Vacuum leaks typically cause the engine to surge a low rpms.

JakeS2

Lemming , no it's not clear. The idle dwells when she warms up so there must be a vacuum leak somewhere. The thing is that I did do anything for the engine apart from belts, rollers and new waterpump + checked the condition of the slider pads under the valve cover.. So there can be almost anything broken :/ Because of the situation I guess I have to open the whole intake system and change old hoses etc...

Whe she has been just started she idles at 1500 and revvs nicely and gives absolutely great performance)...

JakeS2

Could a broken O2 sensor be culprit? Does 968 use lambda before the engine is warm?

JakeS2

This is now fixed. The new MAF and replacement coil did the trick ; we're flying now!