Rotor burn marks

[Dart Gone Fishing]

I was doing a tune up on my 70 Dart. It hasn't been running too good lately. I noticed the rotor had some arcing or burn marks on it. Didn't see anything on the cap though. The rotor had 40k miles on it. I changed the wires,plugs and new cap and rotor. The wires and plugs had 90k on them. Resistance was climbing. One time I drove in fog and the car freaked out.

 

[rustycowll69]

maybe rotor phasing is off. maybe there's moisture in the distributor.

 

[toolmanmike]

It was time. Those old cars used to get tuned up every 12 months or 12,000 miles.

 

[Dart Gone Fishing]

Thanks for the replies. It was an intermittent problem. More noticeable in the morning. I also put in a new ECU, checked carb, resistor, distributor, etc. So far so good.

 

[Murray]

If the "spring steel" contact isn't quite touching the cap contact- some arcing will occur, resulting in what you are seeing. When I do a tuneup, I always bend that tab up to make better contact. Better to be a little tight than have a gap.

 

[Dart Gone Fishing]

I just noticed some flashing on the side of the metal. Looks like they didn't get a good cut. Could of been affecting the spring tension.

Some of the old spark plugs were up to 7.8k ohms. Ignition wires were up to 5.6k per foot. Coil wire was 6.9k per foot. Plus a chafed tach wire resting on the master cylinder cover. I think the car has multiple problems.