Hi I'm new to this site and I have a "strange " problem. Sometimes when the car is turned off (key removed) the car keeps on going, although the rev counter is at zero and everything else is off, even the alarm indicator comes on but the car is still idleing. If you push the accelerator nothing happens. After about 2 - 3 minutes the car stops. I had the car at a dealer and he says has never seen this before and doesn't know what is wrong.
The car has been at the garage about 10 times for a idleing problem namely when you stop at an intersection the idle drops and sometimes stalls and sometimes it settles at normal revs. This doesn't happen all the time and never when the car is cold. Also when the ECU is reset it is fine for a few weeks and then it starts acting up.When the idle is bad I also have a problem sometimes with pre-ignition when I switch the car off.
The dealer replaced the throttle body about 2 weeks ago but the idle problem is still there and now the running on issue has started.
Since the running on is very intermittent, the guys at the dealer wouldn't have believed me if they had not seen it for themselves, they say it will be hard to resolve. I assume that there must be someone who has seen this before, because I don't understand why there are no error codes etc when the ECU must know the car is switched off since it activates the alarm but also the injectors, coils, air flow etc must be activated to keep the car running.
Please can anyone shed some light on this.