I'm trying to help a buddy with his '92 740T. Here lately, the car will suddenly have a skip for an instant and then continue running fine, although when this happens at idle, often the engine will die.

When this happens, the tachometer dips, so I know it has something to do with the ignition system. I've swapped out the powerstage, coil, and crank position sensor with known good units and it hasn't made any difference. I checked all of the engine grounds on the car and they are good.

The only other thing that I can see that would maybe have an effect on the ignition system would be the knock sensor and I haven't tried unplugging it yet, but honestly don't believe that's the problem.

That leaves the EZK computer. Do these units go bad frequently? I've got an EZK from a '91 940T that I can try in it tomorrow.

This is driving me slightly mad...

I read through the FAQ and thought for sure that the CPS would fix the problem, but it didn't. BTW, he has the newer, white-banded sensor.

Any suggestions for something else that I might check?

Thanks!