Hot starting problem

No cold start problem at all. Pump three times and it fires right up. I have a 62 Super 90 Porsche with dual Solex PII-40s. When I've driven it for a few miles and shut it off for about 15 minutes or so, it's a bear to restart. Just an awful lot of rapid cranking with my pedal halfway to the floor as the manual recommends. I just had the carbs rebuilt when I had a new head installed. I've got a fully charged 6V Optima redtop, so plenty of cranking amperage. Do I need to pump it just as I do when it's cold? I'm not anxious to flood it, but have no other immediate solution.

I live in the San Francisco Bay area, so weather is not a real factor. Jim Slawson

What type of fuel pump do you have, Jim?
angela

Three things come to mind, First, check all of your fuel lines and make sure that none of them are getting heat soaked as you drive. If this is the case, fuel will bubble within the lines and starve the engine, (especially noticeable under conditions as you've described)

Angela has touched on Number 2, If you have a stock Porsche fuel pump, it could be failing. Check around for a quality 6 Volt electric fuel pump (make sure it is either internally or externally regulated for 3 to 4 PSI)

The third thing is contrary to the manual, try holding the accelerator pedal to the floor. The more times you pump the pedal, the worse it gets as it's squirting extra fuel down each venturi. Holding it half way can sometimes cause your foot to move around and thus squirting more fuel. If you keep your foot planted on the floorboard, no extra fuel will enter the engine. The other good part about this is extra air enters each cylinder with the butterfly valves fully open.

Verify timing and dwell. Then, when the engine is hot or even warm, pretend you're in a new new car - turn the key on and DON'T press the gas pedal. If it don't start or at least burp, within three or four seconds, THEN give it a bit of pedal. Works for me.