Gentlemen, My car is a 1969 Chevelle Malibu convertible. The engine is from a 1970 Chevy. It was originally a 250 hp engine, but the former owner converted it to a quadrajet on cast iron manifold and HEI ignition. The engine runs well at rpm's above 2000, but the low end stuff like coming off idle sounds and feels bad, shudders, or stumbles, hard to explain, but just plain awful, feels like it is running on 5 cylinders. I have changed out the plugs, wires and rotor. I am about to complete the ignition tune up with new cap. What am I missing. Is this symptomatic of a poor coil? Could it be the springs which are extremely tight? I have not done a compression test, but since the car runs well at speed, I don't think it is a serious issue. Nevertheless, I can't seem to fix this annoying little problem. Any ideas or suggestion how this could be improved would be greatly appreciated. ( I don't think it is a lumpy cam. Not that "hot" an engine. ) What might be the most likely suspects? I may have posted this question two months back, but it never got solved. Thanks in advance for all and any consideration. R.B.

what is the timing set at? base and total...

I think a compression check would be a good place to start.

what is the timing set at? base and total...

First thing to check IMO, then the carb. Might want to clean all the plugs before you begin changing things on the carb, though.

Thanks, I don't know what the timing is set at, but I will find out. The compression test is on the list of things to check, so I will just get a little deeper into the project and post again when I can answer some of these questions. The springs I mentioned were the ones in the distributor. They are so tight that I can't pull them out when gripped with thumb and forefinger. Is this too tight? Thanks, I'll get back to you. R.B.

Checking your timing will tell you if the springs are working. Vacuum advance disconnected, then check timing at initial, then at 2,000 - 2500 - 3000 or until the timing stops increasing. Post back once you check things out.

Friend has timing light. Hope to get this info on line by end of week. Thanks again. R.B.