Quadrajet Air Leak

[mstark]

I've got an air leak somewhere around my carburetor and I can't figure it out. We changed the gaskets between the intake/adapter plate/carburetor. Still if I spray carb cleaner in that area my idle will jump up, and it won't idle hardly at all. It does not leak around the intake manifold... and all of my vaccum plugs are on the carburetor.

I was hoping someone else has had this problem before and can shed some light on my situation.

TIA

Michael Stark

 

[Gummi Bear]

Try a very, very thin coat of RTV to seal the gaskets. It sounds like something's not perfectly flat, and not sealing properly.

Also - double, and triple check that it's exactly the right gasket for your carburetor. If it's off just a little, you can have some serious complications.

Good luck!

 

[mstark]

The gasket appears to be identical to the surface it mates to. I will give the RTV a shot, would it hurt to put some on the outside of the gasket? like from the bottom adapter on the gasket and to the carburetor? like a patch sort of

 

[ugly74]

regular RTV is not going to work. any exposure to fuel, and that stuff turns to jelly. my guess would be that the baseplate is warped.
try dressing it with a fine tooth flat file and see where all the high spots are.
how tight did you torque it down? if it's way too tight, that can cause the warpage too.

 

[SteveL]

Those adapters are never perfect. I found some form a RTV that was fuel safe. It may have been black. Make sure it isn't the carb itself that has a leak. The first ones I installed I thought was leaking at the base but it was the old carb body.

 

[maws75]

Try spraying around the throttle shaft and see if that changes your idle. We used to have to put bushings in the throttle plate because the shaft would hog the aluminum out,pretty common on quadrajunks

 

[scottmcwms]

Use the black RTV like you were caulking the tiles in your bathroom. Put a little on the gasket, install the carb, then caulk the joint. Allow it to cure for 24 hours before you try the carb cleaner trick again. Otherwise you will probably wash it off. If that doesn't do the trick then let us know.

Scott

 

[mstark]

it was the top of the intake, we changed carburetors and it still had the problem so then he put some rtv on the back right corner and that did the trick. i will most likely change intakes anyway sometime in the future as the motor was built for a street truck my brother was going to build up a very long time ago. it has the weiand x-celerator intake on it now.