High Idle

Hi folks - I have two MGF VVC's and one of the has developed an iritic idle.



The symptoms are - starts up ok - revs a little faster until up to temp then settles around 850 which is the same as my other car. Recently when I have been driving it the revs seem to not drop back down at gear changes and can sit at about 2000 revs at junctions etc in neutral. Today I decided to take a look - Having the other identical car I was able to swap known good parts to try to pin point the fault. Things checked :



1. TPS reset - stops fault but fault returns.

2. Changed TPS- fault returns.

3. Cleaned rather mucky ICV - fault returns.

4 .Changed ICV - fault returns.

5. Changed MAP sensor - fault returns.

6. Changed inlet air temp sensor - fault returns.

7. Removed air cleaner placed hand over end of throttle body - revs drop so assume no air leaks ?.



Took it for a drive and at the first junction the revs were high - took off rather rapidly (bit annoyed that I spent hours on it with no improvement) and the problem went away. Went for quite a spirited drive enjoying every minute and no issues yet. Could this be some kind of clogged injectors or something. The car has sat for several weeks with little use as it is the weekend toy.



Any thoughts and wisdom greatly received before the little hair I have left is removed !!



Cheers Marty

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