383 misses at idle

['68 383 Charger]

I have a '68 383 with a Pertronix ignitor in the original distributor, MSD 6A box and a performer 600 carb. Sitting at idle, the engine will miss or stumble slightly, you can clearly hear it. Yesterday I had my timing light out and when the engine stumbles, the timing advances noticeably 2-3 degrees. it is not a random miss, it is very rhythmic and predictable. Has any seen this before? I think it must be in the distributor. Thoughts?

 

[Meep-Meep]

Was it running fine before the Pertronix mod? Go back and check the firing order and other basics. Cross check plug wires and plugs too.

 

[dpstark2]

I have seen this sort of behavior on 3 different cars with Pertronix units. If you have an MSD box, try a set of points instead of the Pertronix. If it goes away- you found the problem.

I don't know what it is, but I've seen the timing dance +/-2 degrees with a Pertronix unit (in 3 different cars). Many have no trouble at all, but if it turns out to be your problem too- you're not alone.

 

['68 383 Charger]

I've had all the parts installed for years, and it doesn't really bother me or run bad, just happened to have the timing light on it and noticed it changed when it stumbled. Now i need to see if I remember how to set up points

 

[Mopars & Missiles]

I have seen this sort of behavior on 3 different cars with Pertronix units. If you have an MSD box, try a set of points instead of the Pertronix. If it goes away- you found the problem.

I don't know what it is, but I've seen the timing dance +/-2 degrees with a Pertronix unit (in 3 different cars). Many have no trouble at all, but if it turns out to be your problem too- you're not alone.

Exactly why I tossed the pertronix in my Challenger. Unstable timing at idle. Figured if it was unstable there, it was probably doing the same thing at higher speeds as well.

Installed an MP electronic kit and runs much better, much more stable.