The 460 in my 1985 E350 box van suddenly started missing bad on all cylinders. It barely does 25mph. When i opened the hood, the Ignition Control Moduel was smoking. I though "aha" this is an easy diagnosis.
I replaced the module, however, and it still misses really bad. Any ideas what it could be?
Some notes:
-It has recent plugs and NAPA wires and new coil.
-I ruled out low fuel pressure by switching over to AUX tank that has its own electric fuel pump. Issue persisted. It has recently replaced fuel filter.

 

Nevermind. I think I figured out my own problem. A fresh engine ground strap seems to have fixed the problem.