Rough Running 68 400

[68 Cutlass S]

I recently rebuilt my 68 Olds w/400. I replace the distributor ignition with an HEI, the stock intake with and Edelbrock performer 455 and the Q-jet with an Edelbrock 600 carb. I'm experiencing a surge in the engine at low RPM's. It almost feels like a miss, but goes away at higher RPM's. I've put new plug wires,plugs,fuel pump and filter, and even run a wire direct from the battery to the Distributor ( I thought maybe low voltage somehow). The HEI distrubotor is new, but it is an in-expensive aftermarket one. Could an ignition module cause the surge, or do they just fail altogether. Any suggestions will be greatly appreciated.

[Olds64]

You can generally remove the HEI module and have them checked at your local auto parts store. They aren't very expensive if they are bad.

[88 coupe]

Originally Posted by 68 Cutlass S

........ experiencing a surge in the engine at low RPM. It almost feels like a miss ,.......

"Surge" and "miss" are two different symptoms, with two different causes. You'll need to clarify.

Originally Posted by 68 Cutlass S

........ but goes away at higher RPM ........

Define "lower" and "higher" RPM.

Originally Posted by 68 Cutlass S

........ Could an ignition module cause the surge ........

Whether it's a "surge" or a "miss" it's highly unlikely.

Norm