Hard Starting - Where to go now?

Posted by Mark Graber On 2012/7/3 1:10:45

Hello Packard Friends and Greetings from the Last Frontier,
Here's the problem with my '47 Custom Super (356) that I am awakening after about a 10 year slumber.

She absolutely will not start when the temperature gauge is anywhere near or above warm (even with electric fuel pump on). When cold, she will start within 5 seconds or so of starter engaging, and pedal all the way down (as she was designed to do). An immediate restart after highway speeds is not a problem, but once she gets warm/hot as from extended idle or city driving, only a 20 minute cool down will get her going again. Note that 75 degrees is a warm day here, so extreme ambient temps should not be an issue, and she has never overheated on me. Cooling system seems perfect.

Things done so far by reputable restoration shop or me, include the following:

1. Carburetor rebuilt and sticking accelerator pump fixed.
2. Full tune-up (new plugs, points adjusted, new condenser(me), timing set, carb adjusted).
3. New coil, new rotor(me).
4. Rebuilt mechanical fuel pump installed (me). Auxiliary electric fuel pump has been installed, in-line fuel filter replaced with new. Inside of gas tank inspected and looked clean.
5. Heat shields on fuel pump and carb are in place.
6. New, strong battery.

As the starter switch is under the accelerator pedal, my resto shop added an extra starter button under the dash in case of flooding. Use of this switch with or without some pumping of accelerator doesn't help - engine just turns over but does not catch.

Rather than launch willy-nilly with ignition wires(look good), voltage regulator, distributor work or other stuff, I would appreciate suggestions on how to diagnose and proceed in a logical fashion to achieve reliable re-starts.
Thanks in advance,
Mark