Erratic Idle, Erratic idle

[seanbrazendale]

Hi

I have a 1999 petrol non turbo 8v Fiat Ulysse, same as the Citroen Synergie/Evasion.

When I bought the car second hand, it would stall on cold start unless the accelerator was used until engine had warmed up a bit. I managed to clear that problem by reseating plugs to senders on the air intake /throttle box. However, that introduced a new problem. On cold starting, engine revs to between 2 and 3k revs and this gradually drops to 1k and remains stable. While still cold, if I blip the throttle revs go back to 2k and slowly drop. Take the car for a run until engine is warm whereupon idle oscillates between 1 and 2k revs.

I'm told that this can be the idle control valve which I have removed and cleaned. The spec for the solenoid windings is 53 ohms and mine are 49. I have pin checked for continuity every sender back to the ECU and all are good.

There are no air leaks anywhere on the air inlet system. If I disconnect the plug to the idle control valve I still get 1 to 2k idle oscillation.

I'm a member of the Fiat Forum and while helpful I find this site to be far more knowledgeable.

Anyone any clues please?

Best wishes

Sean

[demag]

Throttle position sensor Sean? Always seems to be a favourite on petrol engines.

I've known them come loose and not send a true signal to the ecu. Is it single point or multipoint?