528e,533i

[rich2481]

Both seem to idle really high, checking setting on throttle plate is fine .002. but I still cant adjust the idle any lower, than 1500 RPM.

I am beginning to think the part is shot on both cars, if I partly plug the vacuum line then the cars run rough, both have clean oil, clean engines, and no vacuum leaks,

I have sprayed out the part with fluid ( sorry cant think of the parts name this AM) but it looks like the plunger only goes half way, like the spring is worn, I have looked on the throttle plate for a additional adjustment screw but neither car has one, and when I unplug the part, the RPMS go way up,

thanks

Rich

[CraigD]

You may have fixed your problem but if not I would bet that the throttle plate setting is off. I think it is a tweak of the return spring pressure but the butterfly sits off to one side. Depending on where and how you measure you can get a correct reading or a larger reading away from the linkage. I set mine by centering the butterfly as it closes then measuring and adjusting and rechecking everything 2-3 times. My 533i idles rock solid at 700 rpm which is spec and the ICM is at spec per Bentley.

The other likely source is the ICM needs adjustment. See the Bentley for instructions.

Craig