Is there anyone on here familiar with the old points setup on early 7's? I was checking my timing today and at first everything was fine. The timing light was picking up signal on both trailing and leading plugs. After a few more minutes my light suddenly stopped picking up a signal off the trailing wire. I tried the other rotor and same problem. Strong flashes off the both leading wires but nothing off the trailing wires.

I've been trouble shooting it for a bit and have observed a few things. Both trailing plug are actually firing but it appears there isn't enough voltage in the wire to trigger the timing light. If I run the car with the trailing wire off the spark plug and hook up the light to the wire, I get a normal strobe. As soon as I put the wire back on the plug, it stops. I tried different coils but no change. Condensers, points and spark plugs are less than a year old.

Any ideas??

 

it might be the timing light, id try a different one.

that is if it really is sparking

 

Strange that it would work fine on the leading wire though...

 

the stock 79-80 cars shut off trailing sometimes, but id have to look at the book to see when. maybe thats what yours is doing?

 

Turns out you were right the 1st time. It was the damn timing light!