Fast Idle Problem? Is there an idle stabilisation valve.

[paul_23]

Hi

On start up the car sometimes idles at 1800rpm and will stay there until put into drive, or sometimes it slowly drops to 800rpm, or sometimes it starts and goes straight to 800rpm. Can happen hot or cold.

Also, when driving along and braking towards stopping, it feels like the engine is pushing the car and is not disengaging. When stopped (in D) the idle stays at 800. When I put into N sometimes it stays at 800, and sometimes the revs climb to 1700!

Is there an idle stabilisation valve or idle control on these cars? If so, how much cost and how much work?
What about coil packs?
I thought at first it was the gearbox/TC but I think it is the engine/idle.

Any other thoughts or suggestions...

Cheers

[volkscraft]

Try cleaning and resetting the throttle body and get a vag com scan. There isn't an idle stabil valve.

[paul_23]

I did VAGCOM and got no fault codes - any measuring blocks I can check?

Cheers

[volkscraft]

You could log coolant temp when its playing up, a duff reading can cause all sorts of problems. Make sure its a fairly linear curve on the warm up, i.e 10, 11, 12, 14,15. They go a bit like this when broken, 10, 11, 12, -49, 14, -20, 15, 16 etc.

[Rupert]

Is your car down on power at higher revs?
Mine did this when the O2 sensors were knackered, it would pull along at 30mph without touching the throttle! Coming to a complete stop made the revs fall to 800 again.
The lack of power was very noticible by the time the high rev symptom showed up.

[paul_23]

Power is fine all through rev range....

[Shoppinit]

Check MAFs again. I know you had them changed recently, but you never know.

Check the g/s measuring blocks and also the lamba correction to see what's going on with that.

Sounds like mixture problem. Possibly a vacuum leak.

[Cornishmoocher]

Mine did this.... for a week or so..... then stopped and never did it again during my ownership.

[Shoppinit]

Bit like blowjobs from the wife then.

[Cornishmoocher]

^^^^^^^ Brilliant.... and so true!

[Billiemapped]

Bit like blowjobs from the wife then.

Excellect....

[Billiemapped]

Bit like blowjobs from the wife then.

Excellect....

Excellent

[paul_23]

Car went into MTM and they noticed a misfire on some cylinders so they said injectors and coils need doing, which is also causing the high idle. As MTM cant do warranty work I took it to the dealer and they have had it a week and after swapping over some coils they say the misfire is random and not connected to any coilpack or injector so they reckon it is the throttle valve. They cleaned it and say the electrical part of it is fine but the mechanical flap is not working properly and is intermittent.

They say the part (077 133062C) is almost 800 quid and then 1 day to fit it as the radiators etc need to come off the front - much like a timing belt. I am not convinced this will solve it but they are but I am not keen to proceed with the work unless it does cure it.

This is not covered by my warranty (super smashing great NOT) so any ideas where I might get a second hand throttle valve from ? I will try Grizz....

Cheers

[bilko1]

Who's your warranty with?

[grizz]

It's only the front end into the service position not fully off .
I've got a spare one on the shelf

Grizz