Vapor lock... or winter fuel on a blazing hot day.

a few possible fixes.. installing a 10 micron fuel filter directly before the mechanical fuel pump inlet.. this protects the fuel pump check valves from getting held part way open with sediment and reducing the pumps ability to hold fuel in the line to the carb and reduces the pumps ability to pull fuel up from the tank..

when the reduced pressure fuel in the line to the carb gets hot.. it turns to vapor.. the expanding vapor pushes all the way back thru the fuel pump to the tank. leaving your fuel pump almost dry..

don't believe me.. disconnect the fuel line at the carb. blow into it.. you should NOT be able to blow bubbles in the fuel tank...

you will also want to sneak some magnets into the fuel tank.. getting them to the bottom.. so that any sediment gets attracted to them..

i have been fixing this issue since the mid 1980s.

why the motor did not want to crank was because it was crazy hot inside from running lean because of the reduced fuel pressure/flow just before the engine stalled.. the pistons expanded too far and removed the clearance to the cylinder walls making it almost impossible to crank..

water poured across the mechanical fuel pump and the line to the carb will help get your system pumping again.. cools the fuel off slightly.

when i do these installs.. i usually disable the ignition system.. extend the fuel line to the carb into a clean clear 2 liter soda bottle.. do a 15 second full flow cranking test three times into the bottle.. this allows a full speed rush of fuel thru the filter and the pump and many times that will clean out the check valves.

if your carb needle and seats are seeping.. do the previous instructions.. get the engine started... with a LONG nose pair of pliers.. pinch the fuel hose between the new filter and pump inlet. with the other hand take the RPMs up to around 2000 ... when the engine starts to stumble.. release the pliers.. the high speed rush of fuel thru the wide open needle and seat will be flushed by the clean fuel .. this is kinda hard with holley carbs with secondary float bowls.. you can with a helper holding the pliers.. open the primary throttle slightly.. and with the other hand open the secondaries..

please have a wet towel ready to smoother out any carb fires you create doing this.. i have set half the intake on fire on my 460 ford before.. sort of a exciting experience.. as i had no towel.. no extinguisher and i was in my own van.. sounded like an afterburning jet fighter engine while that was burning..

i managed to rev the engine and snap the throttle closed a few times and smoothered the fire in the intake without any burned eyebrows. and for those who say its impossible.. its a dual plane intake with a 4 hole base gasket with a 4180 holley. its a true split system except for the pcv passage..