Technical Engine over-revving on tickover

[wolvescinq]

Hi all!

The engine on my Cinq Sporting has been over-revving on tickover for a while now (typically between 1200-1500rpm) even once warm. Is it weather-related, given the recent Arctic conditions? It occasionally drops down to 1000-1100rpm, but the next time I blip the throttle it settles back on the higher revs. Touch wood car drives OK, but I'm thinking I must be getting through more fuel than usual with this happening?

 

[jimbro1000]

It is either an air leak or a faulty sensor - both have the same symptoms

If it is simple over fuelling it is likely to be the map sensor (or the pipe to it) or the lambda sensor.

If the revs wander wildly then it is more likely an air leak in the induction system.

The water temperature sensor can also upset the idle speed, as can the tension on the throttle cable.

 

[fingers99]

Also check for sufficient slack in the throttle cable and that the rubber nipple on the end isn' t fouling things up.