In-gear idle issues

Eddy Hoover said
Hello everyone,

Hopefully I am posting in the right spot.
I have a 1973 Dodge W200 (360 LA). The engine has been rebuilt with a mild cam and an edelbrock 1406 4 barrel.

For years I had an msd streetfire box and coil that worked beautifully. Unfortunately it become necessary to put back on the stock style system. I bought a new box and distributor(not points) and got it to pass smog.

My issue today (a week after changing ignition systems), is that the engine runs and cruises smoothly, but starts hiccuping when in gear and stopped or coming to a stop. It will sometimes idle at several stop lights perfectly and then it just starts acting up. I can keep it alive by throwing it in neutral, but I want to get this fixed once and for all.

Ignition switch and 4 point ballast have been replaced; As has the wiring from the ignition box to the coil and distributor (box and distributor came in a kit)

Any help would be appreciated.

Ps. I believe the ammeter has already been bypassed. And after smog, advancing timing has increased idle quality

So the engine was running fine and performed well with the MSD box & coil, and you went back to the OE style setup just to pass smog? I would be inclined to go back to the MSD setup and put the OE setup back in when you need to get your smog test. Like halifaxshops said, the orange box ECU may be flaking out on you. I agree with what RRR mentioned, 25 degree advance is huge for a basically stock engine. Do you have someone with a known-good ECU that you could borrow just to eliminate the ECU being a problem?

Also the Blaster 2 coil does not need a ballast resistor. Ballast was for OE style coils and to prevent burning points, neither of which you have. You might want to try bypassing the ballast resistor to see if giving the coil the full 12v will help your issue.