Erratic Idling

I have recharged the battery twice in recent months and on both occasions after refitting and running the car, when idling, the engine can idle between 500 and 750. When running it runs perfectly. The first time it reset itself after a short time but not sure this time as I am hardly using the car. Any ideas. Mk 3 07 plate on 39,000 miles.

HI

after battery removal, I have solved this by just letting it idle for 20 mins, and also do the steering lock to lock things to turn the DSC light off.

I think there are posts covering this I have read

this was what i was thinking about

I had weeks of this until I followed tips via Bettabuilda completely removed terminals tapped the cone collars down with a rubber mallet reconnected giving them a tap again…there now that tight you can see the collars bending…

Put the key in position 1 for one minute turned off 1 minute…started car let Idle for 20 minutes then turned every electrical item on and let Idle for another 5 minutes…then did the DSC reset then went for a 20 minutes drive,…it now drops and stops at 800 like hitting a brick wall…best it’s ever been since purchased a couple of months ago…fingers crossed it stays this way