*****Start with a engine compression test**********. The secondary side of the ignition system is the usual suspect. Inspect and replace cap, coil rotor, wires, plugs as required.
A Hot aftermarket coil need s steel center pin on a HEI. The stock resistant carbon center pin will overhat and burn the cap and rotor with anything but a stock GM coil. A common fault MSD makes the steel pins that go with their swap in HEI coil.
Carb may be flooding ( fuel filter, dirt in needle seats) this will foul the plugs.
replace the plugs and fix the carb. Blown power valve will do the same thing ( back fire thru carb blows the PV).
Fouled plugs will idle but will not take throttle load. ( misfire)
They rarely can be cleaned once carbon fouled. replace.
Idle fuel pressure not more than 7psi.
Look for and fix any all carb/ manifold vacuum leaks. Broken hoses etc
Make sure the engine is grounded to the firewall with a ground wire and good contact points.
Google search: vacuum gauge diagnostics, then go buy one and use it.
Last edited by F-BIRD'88; 05-23-2012 at 12:18 PM.