Idle Problem

[thegrimm]

Another newbie here

Had my is200 auto for about 5 years now it's only done 63k and it's on a x plate, anyway I have a few issues which I need sorting but the main one at the moment is my idle.

The car is fine when you start it from cold then after about 10 mins of driving my tick over is about 500rpm and sometimes is stalls when coming to a stop, the thing is after about another 10 mins of driving it seems fine well better but still a bit low I have had the throttle body and idle control valve cleaned but no joy do I replace the throttle body if this is the problem any help would be well accepted.

[steve2006]

Hello and welcome to the LOC.

You have covered the main culprits but have you considered with it being temperature related the coolant temperature sensor, there are normally 2 of these one for the gauge and another for the ECU information.

If the sensor is faulty it could be telling the ECU the engine is still cold when in fact after 10 minutes it will be fully warmed up but the ECU will still be fueling for a cold engine and therefore over fueling and possibly causing the symptoms you have.

You can measue the voltage on the sensor cold and hot to see if it is correct for both situations but for what they cost it may be better to just replace it.