Ok working on a 502 MAG with MEFI-3 ECM. After some motor work I set the base timing (with Mercury hand held) at 9*. The problem is i'm not getting any advance out of the distributer when rpm increases and I am thinking it is the Ignition Module in the distributer? I have ohm the coil inside the cap and it is good and the advance ring in the distributer is moving freely. I doubled check that it wasn't in "base timing mode" by unplugging the diagnostic tool. The new module is on the way and was wondering if I might be missing something?

Coil in the cap? Advance ring?
I had a MEFI 1 system. It used the standard small cap GM distributor. The only moving part in it it was the shaft, and advance was controlled by the ECU.

Ignition module was the fix!!!

Thanks for reporting back.