1967 Chevrolet Corvette cold start problem

Runs fine when it is warm so it has to be something with a cold starting engine having to do with air, fuel mixture, not being right for cold engine. Could also be an ECM issue.

COULD BE A HOT SPOT WHEN YOU SHUT IT OFF THE OIL BURNS OFF AND THE COLD START IS THE DRY LIFTER AND ROCKER CONTACT OR THAT SPRING IS WEAK UNTIL IT HEATS UP AND EXPANDS TO CLOSE THE GAP BETWEEN THE ROCKER AND THE VALVE STEM

not starting when it gets warm could be a starter problem, the amp draw is probably to high for the battery to supply enough power to start. starter draw should be around 150-200 amps. the black gray smoke is too much fuel that isn`t being burnt. if the starter draw is too high then there isn`t enough voltage for the ignition system to fire the plugs properly causing the smoke.

Two things come to mind,on your holley did you put fenalic spacer plate between the carb and the intake manifold? OK maybe i shouldn't have used the term fenalic but I mean a spacer or adapter plate between the carb and intake manifold. Any ways I've found that a lot of times the gaskets that goes under the adapter plate and the intake manifold leak and you will have a severe vacuum leak. There's a couple of easy ways to check. Just feel under the edge of the plate and see if you can feel a leak or you can use some starting fluid and with car running of course for this and the first test anyways with the car running spray around the carb and intake manifold and if the engine speeds up or just smoothes out then you have a leak. Or with the 650 cfm double pumper does it have a manual or electric choke. Because either way your choke may need to be adj

You need to have the choke adjusted so it runs on a fast idle so the engine can warm up or you may need the carb to be rebuild and adjusted properly.

fuel pump

time to replace the starter solenoid

i want to give you the right answer but the only thing i think of is the mass air flow sensor.

Coolant temperature sensor is bad. Telling computer that the engine is still cold and over fueling as if it were a cold engine.

could be vapor locking, losen up the fuel cap and see if that helps if so then replace it!!!!!!
and chane the fuel filter also