Need help with my zz502

[Big Block Bill]

Originally Posted by drdave69

By the way this is in my 1966 Corvette. The Holley is no longer on the engine. It has FAST EFI now. I recently checked the ground strap from the engine to the front crossmember and cleaned the surfaces. I also installed a second ground strap on the other side of the engine to the frame rail (with cleaned surfaces).

The 502 has the HEI that came with the engine 12 years ago. I bought another new coil this past Saturday, installed it and it did not cure the problem.

I do not know how to hotwire it but I will check the voltage when cold and hot.

Thanks for the info.

Make sure the metal ground strap under the coil is present. It goes from a coil mounting screw to the cavity in the cap next to the 12 volt power supply. I had a Cadillac that drove us crazy from someone leaving it out when they changed the cap / coil. Just an idea FWIW.

Bill