So the symptoms are.... runs fine but stumbles (minivan). I guaged the feul system and it checks out fine. It has a new pump. Then I put a test lamp on the + pin on the coil and I see the lamp go out intermittently when the engine stumbles. A while back I posted here with a problem, I had a puff of smoke escape out of the steering column twice, nothing severe but it was noticable. I suspected an ignition switch problem, but that was months ago and I have not had any problems until now. I removed the ignition switch and took it apart to see if anything looked burned inside and saw nothing unusual. Unfortunately tiny ball bearings flew out of the switch and were lost in the gravel so I'll definitely have to replace it now. I'm leaning towards either an ignition switch or computer connection problem. Any other advice?