Can you pop in a diff dist?? Or can you put a vac source and watch the plate come around and see if somthing is grounding or if the gap is changing alot.

I ask this because I chased the same deal and did everything from fuel pump to float level, coil, ect only to after a long time find the cause was the advance plate had issues when it was moving in the advance of the dist plate..?????

Who knows, but good luck.