Another project e30: 1990 330iS

[ViPER1313]

Have you looked through this?
<!-- m --><a class="postlink" href="http://forums.bimmerforums.com/forum/showthread.php?t=407255&highlight=runs+rough">http://forums.bimmerforums.com/forum/sh ... runs+rough</a><!-- m -->
If you can get through the 200+ people who had faulty o2 sensors, there's actually some legit info in there.

I don't think it's the grounds either, when I did my swap I was missing two grounds and the car ran fine. One of the coil grounds, and the coil from the block to the motor mount. I drove the car to the dealer to buy replacements.

He stated he already replaced the O2 sensor, no change.

On my car if the ground to the ignition module is loose on an SHO it will cause all kinds of hell. A corroded wire to the coil pack or any of the major wiring harnesses can also cause havoc.

Hell, the SHO my friend bought for $150 was sold cause of a missing ground wire. Fucker spent 3 months messing with it, finally gave up trying to figure out why the fuel pump wouldn't prime. After 5 seconds I realized the car was missing the ground from the battery to chassis (the terminals had been replaced.) Installed, 3 cranks, car started right up 8)