When starting the car from cold, the revs are up a bit as expected (about 1200) but fail to decrease although the car is warmed up but if the engine is turned off and back on again, the expected idle of around 900 is evident!

It does this without exception each time and there is no faultering or erratic idling, just either of the two figures of revs.

 

My only thoughts are to do with the water temp sensor/connectors or possibly an air lock which sorts itself if the engine is turned off?

Have a wiggle of the tps sensor connections when its idling fast. Sometimes that connector can cause this.

Have a wiggle of the tps sensor connections when its idling fast. Sometimes that connector can cause this.

 

Cheers Willie, I'll give it a go.

TPS seems to be fine - any other ideas?

Watch that there is the connector onto the end of the TPS and another connector on wires going just below the TPS. It was that connector below the TPS that would make mine idle high and it would drop to normal when that connector was given a wiggle. The issue seems cured now and I never identified exactly where the problem was just that the wiggle of those wires always made it settle down.

 

Worth checking and carefully cleaning any green oxide out of each connector.