Originally Posted by hauss667
So I was having major issues with my quadrajet and instead of taking on the daunting task of rebuilding a carb foreign to me in two days I decided to re-jet and rebuild a 650 carter afb I had laying around. So everything went smooth the floats are adjusted properly everything is in right but now the truck wont idle and you have to feather the gas to keep it going. It has no choke as it originally was off a circle track car and it ran fine on my 350 with no choke just a little cold blooded in the morning, but if i stick the choke closed now the engine idles but even if I wait until it hits temp as soon as I open the choke back up it sputters and dies
It wouldn't idle better w/the choke closed unless it's getting extra air from somewhere other than through the airhorn. So it sounds like there's a major vacuum leak. Check the base gasket, the PCV hose and valve, and all the other vacuum ports and accessories that may be connected to the carb to see if you can isolate where the extra air is getting into the engine from.
Less likely but still a possibility is there's nowhere near enough fuel reaching the engine, so the choke needs to be used to get the air/fuel ratio rich enough to run. That could be from too low floats, sticking needle and seat, wrong or faulty gaskets, wrong jet/rod combination, too large air bleeds, etc.- but most of these things effect the idle a lot less than elsewhere.
What happens when you screw the idle mixture screws out? In? As in, do they change the idle at all, or are they unresponsive?
What did you jet it to? What was it originally?