Thread: Fires....But will not run on its own?

Tweet

Hey guys, my 400 small block is firing now. But it will not idle on its own. I have to play with the throttle to keep it running. As soon as I let it be, it dies. I know its getting plenty of gas to the carb. I am running a 2 barrel holley right now tho :l. Could it just be that the carb is not giving the engine enough fuel on its own? I would think even being a 2 barrel it would be enough to keep that 400 idling. Any help would be appreciated! Thanks, Josh

ya need to go back to basics check for vacuum leaks hoses or carb mount and any place you might find one and come back and give us more info we are happy to help you just need more info....ted

First thing that hit me too was vacuum leaks. Maybe you missed plugging a hole on the carb or intake. Could be so many other things though.

Don

Does the engine run OK at higher speeds or do you need to keep "blipping" the throtle? If it does, perhaps your idle speed adjustment or mixture screws just need adjusting. Could also be a clogged passage in the idle circuit esp. if the engine or carb has been sitting for a while. Gas these days gums up very easily.

Thanks guys, Ill keep poking around. i need to keep bumping the gas even idling at higher speeds.....but now that I think about it, I think i have a hole for the brake booster fitting on the intake thats just open right now. Would that do it?

Originally Posted by Jsmith

but now that I think about it, I think i have a hole for the brake booster fitting on the intake thats just open right now. Would that do it?

OH YEAH! That'll do it!

Every time

Yep, that would be a MAJOR vacuum leak.

Don