I've a Peugeot 406 Saloon Petrol 1999- 1.8. I recently experienced a very high erratic idling that increases the rev counter substantially to a TR/Min of 40 on the dash board. This occurs immediately after starting the car and this high revs continue right through my journey. Two electricians advised me to replace the idling air valve but after replacing it with a new genuine Peugeot part the problem sounds worster(TR/Min.40). What possibly could be wrong? Would appreciate if you could come up with some ideas.
I apologize for only responding now. There are no warning lights coming on at all.