Bad wires or connections can cause delays in spark delivery so while thinking about knocking or timing the wires would not necessarily cause an early firing but power loss is definitely in the mix for sure.


While I was searching for the cause of rough running the first min. after the cold start (which turned out to be the FPR), I also checked all ignition components.

With an Ohmmeter I measured the leads and oh boy, out of five (yes, 5) three measured infinite. This didn't really cause any misfiring but after the replacement, the enigine ran smoother at highway speeds. But, they didn't leak to other parts (the head), nor did the plugs themselves, a friend of mine once had three new plugs fail on a Mustang 289 V8 after a short while, so it happens.

I agree now the first check should be the running the engine in a pretty dark environment and look for the tell tale blue flashes.

Good luck!