W124 300TE-24 Idle speed

[dstrong]

Our 300TE-24 has aircon fitted which I think is responsible for the low idle when warm. After a run when the temperature gets to 95 ish the idle speed drops to 400-500 rpm. Turn off the aircon and it picks up to 600ish. My question is... how do you set the 'base' idle as I can on my Saab 9000. I suspect that the idle speed control valve cannot open far enough and I thought that is should be possible to open the throttle a bit. The procedure on the Saab is to get the engine nice and warm and adjust the idle up until it can no longer be controlled by the valve, then back it off a bit. This makes sure that the valve can let enough air past.

Thanks

Darryl

 

[talbir]

Are you checking idle speed with car in P or N ?

Idle speed should INCREASE when air-con is switched on and compressore enagages. Same when turning the power steering on the car when stationery.

Idle speed on your car, at operating temp, in Park or Nuetral, should 650 +/- 50 rpm and 750 +/- 50 rpm with air-con switched on. In 'D' it will be lower by 100-200 rpm.

Idle speed cannot be adjusted seperately on this car - the idle air valve is what controls the idle speed. If you disconnect the 2-prong connector on it, idle speed should jump to about 1500rpm, which means it's opening fully.

You may have a lean mixture. I reccomend getting the car tuned up by a tech with a proper co and diagnostics machine hooked up to the XII diagnostic port to ensure timing and CO are correct.

Talbir

 

[dstrong]

The idle increases when I put the car in N, it is only low when it is in D with aircon on and hot.