I swapped out my Accel coil in favor of an MSD the other day. After about a day on the new coil, the car starts running rough. Assuming it was the new coil, I put the Accel back in. Same thing. The problem is, it runs rough warm or cold and then for a few minutes it may run fine, again, warm or cold. By running rough, it feels like it's missing, but the RPM's really don't change while it's doing this. When it's at it's worst, the stick shift will shake a lot, but a minute later, it'll be smooth as silk again.

I'm pretty sure it's a short somewhere, I'm just looking for anyone who's exprienced something similar. I don't think it's the coil wire, but I have yet to swap that. The plugs and wires are all new as of May. Again, this all started with the swap of the coil. Before that, it was running fine, but I was having some hard starts. The old coil had a corroded post and did not look to healthy even after cleaning it.

One thing I should mention is that one of the coil ground wires was completely disconnected and possibly causing my hard starts, but I had re-crimped it and it's been connected ever since the coil swap.

I'm open to suggestions, but if anyone has the part number for the GM coil wiring harness(es), I would appreciate that as well. My initial guess is that one or both of the wires that go to the coil are shorting. I base this on when I attempted to push them in harder while the car was running and the car nearly died right there. Once I let off, the car went back to a normal (rough) idle.

 

More of a TTT, I would like to get some ideas before I start ignition roulette. And no, I don't think it's the Opti. I've already been through that and I know what a bad Opti acts like and this isn't it.