DavidVonNicolai

Stock 1974 454 4 speed no AC. Got the car last summer. Had no thermostat, added a 180 degree. Since then, will not start when hot, must let sit 20 minutes. Have used 93 octane with ethanol and 90 octane ethanol free. Had carb professionally overhauled. Car runs perfectly except for hot start. Always cranks just fine. Timing by the book, engine stock sans air pump. New fuel tank, fuel pump, fuel pressure tests fine. Any ideas please?

MelWff

When hot and turned off, look down the primary side of the carburetor and see if gasoline is dripping down the primary side of the carburetor.
I assume when hot prior to turning it off it runs with no problem which would eliminate an ignition issue.
What is the fuel pressure?

Mrvettenick

Yep....sometimes the needle will stick by itself. If that's the case, you should replace the needle and seat.

derekderek

first, try with foot flat on the floor. may have boiled fuel into intake and flooded it. then check hood clearance to air filter. loosely wadded up piece of aluminum foil on filter and close the hood. if enough room add some kind of insulating spacer between intake and carb. homemade wood works best. phenolic is easier.

CheezMoe

Vapor Lock?

DavidVonNicolai

Thanks to all, will try and let you know