76 530i AT Idle issue?

[canada karl]

Hello The car is new to me and I have been restoring the brakes and bodywork.It hasn't run in a few months. Car starts fine and will idle around 800 rpm. As the car warms up the rpm increases to 1200 up to 1500. This is with the car stationary. If I kick the pedal down a bit rpm will go up to 1700 and stay there. AFM is clean...plugs and wiring good... new dist cap ...Pertronix. Last time I drove the car I didn't have any issues so I am reluctant to start mucking about with the idle settings but it looks like I will have to. Seems like the throttle may be sticking somewhere? Any thoughts?

[Mike W.]

Check the timing along with the vacuum retard box on the distributor. Too much advance and it'll seem to run better, more torque, but other odd things like idle speed happen.

[canada karl]

The odd thing is that the idle was fine until I put in a new dist cap because the old one had a lot of carbon on the copper transfer points. I thought a new cap would improve things but maybe the last person to set the idle did so with the bad dist cap?

[528i-1981]

It's entirely possible to rotate the distributor body while replacing the distributor cap if the mounting bolt is not tightened down firmly. This happened to me when my car was new to me. The presence of carbon on the cap contacts would increase resistance but not affect idle in this way. I would start with the timing as Mike suggested, and making sure you have no leaks in the advance and retard lines.

[tlake]

The odd thing is that the idle was fine until I put in a new dist cap because the old one had a lot of carbon on the copper transfer points. I thought a new cap would improve things but maybe the last person to set the idle did so with the bad dist cap?

There is an adjuster for the idle speed. Try lowering it and see what happens.