Fiesta engine idle problem

[bobby]

Hi

I have a mk4 fiesta (1996) which has a problem with the engine idle speed when the car is moving. Whenever I change gear the engine over revs massively, and more concerning is that sometimes I have to drive with my foot on the brake in order to maintain a constant speed. However, the idle behaves normally when the car is stood still (ie normal tick over, and revs fall away as you'd expect).

I took my car to a garage, and they changed the road speed sensor on the gear box, which did nothing to help the situation. They then suggested it was probably the ECU which needed replacing, which would be a very expensive job and probably not worth it. Can anyone confirm this, or give an alternative diagnosis?

Thanks

[delleropk]

Hi mate,

I have the same issue, but with the addition of it never starting first time without the help of the accelerator.

From my research i've been hearing alot about the idle air valve controller, I'll hopefully get a chance to try this out tomorrow.

Danny.

[bobby]

It's nice to know I'm not alone! Let me know how it goes.

Cheers