Hei spark problem

[jsf74]

I'm trying to fire my motor and loosing spark. I get a good spark for the 1st couple of revolutions and then nothing. I've tried new cap and rotor and swapped modules and it does the same thing. Stumped? I have a multi meter but I'm no guru like some of you guys. It's a DUI hei if it matters.

[powerslide]

Pin sheared in the dist gear? Chased that for a month once. Didnt do exactly what you described but worth a look.

[Egoracing]

Bad ground on the engine.

[jsf74]

I think I had a bad coil? It's still fairly new but I swapped in my old junker and it fired right up. Any way to test a coil?

[ToddSmith16]

Check the ground!

[DCM_Doc]

Hei

I just finished working on a friend's 4 wheel drive with a GM HEI. He had replaced the module like you did. I checked & replaced the pickup coil. The engne started but only ran a few minutes till the coil (the main coil in the top of distributor) got hot-I mean HOT! it smoked. The problem was the after market tachometer. I questioned him more & he said the previous coil lasted a few minutes & got hot. I disconnected the tach & replaced the coil & the truck is still running. I had never had this happen before but the problem was clearly the tach. I thought I would pass this on because it took me a while to figure it out.

[9car]

did the same thing , finally jumped out the ignition switch and that was it , vibration had gotten to it

[jsf74]

I forgot about the ign switch. Will have to remember that one.