I finally got my car back together. It was apart for 1 and a half years. I redid a lot of the wiring and rebuilt the motor. The problem is that the engine has a severe miss (breaks up very badly, all cylinders) between about 2300-2900 rpm. It is definately ignition related I feel. The tach need goes crazy when this happens. Below 2300 it is fine and when the engine hits 3000 rpm the problem completely disappears and runs fine. The engine is a sbc with HEI distributor (81+ model without mechanical advance, the engine has an aftermarket efi system which controls timing). The timing is set ok, the rotor is indexed ok. I did take the ignition module in the distributor to the auto parts store and they checked it and said it is ok. I don't know if their test could catch this problem.
I did accidentally hook the power wire for the distributor to the tach output and put 12v to it. I wouldn't think that would damage the magnetic pickup.
Could this be the module or the mag. pickup.
Any help is truly appreciated.