Odd idle!

[jmec]

Hi, Idle on my 325i cab seems a tad erratic. It sits, when warm, just under/on 1k. Sometimes it settles to about 750/800 sometimes it doesn't. There seems no pattern to this regards to weather/driving conditions. The TPS clicks when it should. Any thoughts/advice would be gratefully received. Thanks JJ.

[aimlessrock]

I will start off with one of the most obvious questions, when were the injectors last overhauled?

[Speedtouch]

Try cleaning the idle control valve (ICV);

http://www.e30zone.net/e30zonewiki/index.php/ICV#ICV

In addition, check all rubber vacuum hoses around the throttle body for splits/cracks, and the intake manifold gasket; try spraying WD40 around it with the engine idling - if it briefly alters the idle speed, you have a leak.

Also, check your ECU number; later 0 261 200 380/381 types were reknowned for blowing diodes in the idle control circuit, which can cause such problems.

[jmec]

Thanks for the feedback.

The injectors were overhauled a couple of thousand miles ago and I cleaned out the ICV around about the same time. I'll probably give it another clean up just in case. New boot fitted, again, around the same time. However I'll try the spray around again then if no fix start delving into the ECU. Thanks again...

[Yeti]

check the tps is clicking or check you have continuity through two of the pins in the shut position as that tells the icv to take over.if its that it will cause the iratic idle. had it on mine found the tps not set properly. reset it then has been sweet ever since like 2 months ago