very high idle speed

[kabaman]

So....having got to the bottom of why the ECU didn't want to play ball at all, the engine now starts and sounds pretty crisp but idles at around 2.5 to 3k rpm.

The obvious cause I would have thought is a vacuum leak on the inlet side but I'm pretty sure this is all good.

I don't want to start pulling stuff apart on the I/L side that I already think is ok.

Any ideas anyone? I've tried "crimping" the hoses on the I/L side and disconnecting the stepper motor which make no odds.

Cheers,

Neil

[dnb]

Does it still do it if the pipe feeding air into the stepper is completely blocked up?

If so, then it's either an air leak you haven't found or the throttle butterfly is not returning to the fully closed position correctly.

[kabaman]

Hmm, one of the coils in the stepper motor/idle valve is broken. Looks like this is the culprit.

N

[kabaman]

stepper motor changed - idle perfect :-)