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.

 

If the distributor rotor and cap are original quality items, and not some WalMart house brand imported POS, there should not be interference between the two. If the parts are suspect, replace them. If the contact and interference continues, your distributor may be worn, incorrectly assembled (rotor not fully seated on the shaft, bushings shimmed high, or gear pinned in the wrong position), or the oil pump shaft may not be fully seated or too long. Normally, the cam gear pulls the distributor shaft downward, so that type of interference is not a problem. Improperly molded replacement parts, incorrect parts, or the other problems mentioned could cause that kind of contact between them.

That could affect the operation and cause your ignition problems as well.

 

I replaced the rotor and cap about 2 weeks ago and the new one already looks worse than the old one. I'm pretty sure that it's seated on the shaft properly, but I'll check again.

Will a worn distributor run great when cold and then start messin' up as it warms up?

I've been chasing this problem for the last month and now I am ready to sell this thing!