If you are having trouble starting the motor when hot with locked timng + a interupt switch + start retard, you have a weak starter motor,solenoid or bad wireing or corroded +/- battery cable connections.
You would not believe the difference freshly cleaned battery/starter motor/engine-chassis ground connections make for starting,battery charging/alternator function etc. This is a once a year required maintenance that everyone overlooks. Especially of your car is stored for the winter.
By not employing the vacuum advance for what it was intended for.
(light throttle/load part throttle high speed cruising timing adjustment)
You make the motor work harder, waste gas and run hotter.
When doing a hot restart, crank it over for a good 1-2-3 count before reengaging the spark. ( when the motor is hot) the hot intake manifold is full of non combustible air fuel mix that won't light because it is just way too rich. By cranking the motor over with no spark and just a bit of throttle you will purge out this super rich hot mix and draw in a fresh high combustible air/fuel mix that will fire instantly when you give it the spark. Do not pump the throttle, just open the throttle a little bit to let in fresh air, crank it 1-2-3 then throw the switch on.
Try that when using the interupt switch to hot start it.
The starter will only be under a high load for a split second as it will fire instantly without a long crank time under load.
When running around with full vacuum advance when at WOT I can see the potential for a distributor cap/rotor phasing alignment issue that can result in missfire. The vacuum advance effects the cap/rooter phase alignment.
May want to check that. (the rotor and cap terminal are too far away from each other then the spark fires.) you can check this with an old distributor cap modified with a viewing hole and a timing light.
Last edited by F-BIRD'88; 06-01-2010 at 04:10 PM.