I've been chasing down a demon in my electrical system. My car runs fine cold and as it warms up it starts spitting, sputtering, bucking, jerking, backfiring, and stalling! You name it, I've replaced it! Here is what I found and didn't pay much attention to. The rotor is wearing off the little plastic nubs on one side. It rubs against the distributor cap. Can somebody tell me what this means and could it be the source of my maro running like a POS as it warms up?

Items replaced: fuel pump, fuel filter, plug wires, rotor, dist. cap, oxgen sensor, computer, and ignition module.

 

One thing that it could mean is that you don't have the rotor fully seated on the distributor shaft. Another thing is that it is loose and sliding up on the shaft as the engine is running.