[BryanH]

Last night I replaced the coil with a previous one and had no change in the way the car ran. I also tried wiggling the wires, and that did nothing.

Then I put my timing light on each plug wire as suggested by engineer, and all looked good except cylinder number 8, which was very sporadic. It looked like it was not firing more than it was firing. Then I put the light on the coil high-voltage wire, and it looked like there was a miss there too. Then I swapped the cylinder 8 and 6 plug wires to see if the plug wire was bad, but 6 stayed good and the miss stayed on 8.

The miss on cylinder 8 made me think the distributor cam might have a bad lobe, but the fact that I could see a miss "upstream" from there at the high-voltage wire makes me wonder. Is it possible for faults to cause bad readings "upstream"? Could a bad spark plug in no. 8 cause the bad readings I saw at both the plug wire and high-voltage wire?

Any help appreciated.

Thanks,
Bryan