Rebuilt QJet from Cliff not running right

In addition to fixing the vacuum leak, I would make some studs to attach the carb to the intake. Using bolts in aluminum will end up stripping out the threads. Stacking up gaskets and spacers also changes the amount of thread engagement in the intake. The bolts can bottom out, or not catch enough threads.

All symptoms indicate a pretty big vacuum leak someplace. If it were a flooding issue, you've have fuel running out of the carb at the boosters, accl pump hole, and maybe the front vent as well.

A neat way to fix a flooding issue, is to let the carb go empty by shutting off the fuel supply. This drops the float to the bottom of the bowl. When it re-fills, more times than not, any small debri stuck in the needle/seat assembly is washed out. Saves having to pull the top off the carb in many cases.

I run all carburetors on a test engine for at least 30 minutes before they leave here. We make sure the choke works, and that we have full control with the idle mixture screws, and APT at part throttle.

I'm not familiar with that intake, so can't advise what combination of gaskets or spacers is required to use a later model Q-jet on it......Cliff

 

Thanks for all the help everyone. I ordered the 1/2" spacer last night, should be here Monday or Tuesday. I must be an idiot when it comes to searching, I spent over an hour trying to find one.

Cliff, I know you're work in impeccable, which is why I was real hesitant to make any adjustments to the carb iteself other than the idle screws.

I'm using a set of Q Jet botls designed for 1/2" spacer, but if need be, I'll take your advice and make some studs up for it.

 

Oh, and from what I've read the Eldelbrock B4B and Performer both perform nearly identically. The main difference was the Performer had the Carb mount set in the correct position so you could use the GS Air Cleaner with it matching up with the hood scoops. At least that's what the testing done in Car Craft showed.

 

:gp:

I know what you are saying however it is required that the idle mixture be set on any carb after a rebuild AFTER it is on the engine.

 

I got the 1/2" space installed today and that solved the problem immediately. Car fired right up and warmed up easily. Once warm, I got the idle adjusted to around 650rpm and it held steady. Took her for a test drive and it ran like a champ.
I'll get a vacuum gauge this weekend and set the idle mixture screws as well.

Thanks for the help everyone. It was a simple fix, but I'm sure I would have been chasing this issue a lot longer without being pointed in the right direction.

 

You can generally assume that the carbs rebuilt by Cliff or Tech8 are good to go. If there's a problem it's generally on the install with something being forgotten or connected wrong.

Gotta love them simple fixes though :beers2: