Lumpy Idle

[lowd239]

I just swapped a m20 into a friends '87 325is after his timing belt broke and did a number on his engine.

The swap went well and only took about 4 hours, but the engine idles pretty roughly and sounds like its cammed. Its not what seems to be a surging idle which Ive heard is fairly common in e30s.

I checked for intakes leaks numerous times and found nothing. I cleaned out the MAF sensor and the idle control valve and made sure both were working properly.

Any ideas what could be the culprit?? Perhaps the throttle position sensor??

Thanks!!

[jlevie]

That sounds like intake leaks to me. Take the car to a shop that can do a smoke test.