My 1974 xke with 29K miles was running perfectly and then started missing. It runs well still but I think it is running on 11 not 12. Turns out the new spark plug wires I installed about two months ago are splitting. 8 out of 12 are split. I am not happy about that. I taped them up until I get a new set but it still is not right. Is it possible to foul a plug and it stay fouled until I clean it.

I have a new SNG Barrett ignition and everything else is new. I hate doing the same job twice due to bad parts.

No vacuum leaks or other apparent problems. I guess I am going to have to pull the plugs again and do a compression check. Not easy.

 

I would certainly hope that the wire supplier would stand behind them. (Though glad to read further that it was an engine miss and not that your car had been stolen!)