View Full Version : Cold Starts Chevy 468
nashtychevy
02-22-2013, 08:38 AM
Only 350 miles On 468 BBC ,750 Holley No Chocke ,Why Do I Have To Pour Gas In Carb When Its Cold To Start ,When Its warmed Up No Problem ,Carb Is squirrting Gas Thanks Nashty chevy
mopar1968
02-22-2013, 05:00 PM
Well first of all, In my opinion a 750 isn't big enough for a engine that size, I tried a 750 on my 440 Mopar in my Challenger same problem as you have bought a 850 and it starts and runs fine cold or warm :!: JMO
Mark
ken0069
02-22-2013, 11:28 PM
EDIT
jmarksdragster
02-23-2013, 09:28 AM
It has to to do with the amount of vaporized fuel and combustion ability of the engine. A pump gas engine with lower compression will not burn the fuel as easily, so it needs more vaporized fuel to get it to light. Since it's cold, you have no heat in the induction to help, so you have to add even more fuel to get enough of it to vaporize. Add to that a larger cam with lower vacuum at idle and it's even worse. If it's a street car a carb with a choke is the way to go, if it's for race only you can just pump about 3 times before starting it. One other area depends on what 750 it is, the newer HP carbs have a relocated idle circuit that makes it harder to pull fuel through the idle circuit. The idle jet really needs to be at the bottom.