Cliff's Quadrajet Parts and Rebuild Kits

Quadrajet Problem Solving => Diagnose a Quadrajet carburetor problem => Topic started by: Mike X on September 22, 2008, 03:09:43 PM

Title: Vacuum leak at idle
Post by: Mike X on September 22, 2008, 03:09:43 PM

Carb No. 17054931.  Won't idle.  Sounds like it's sucking air.  Carb ran fine except for stuck needle and seat, so I cleaned it and replaced the needle and seat.  A close examination of the bowl gasket shows deep imprints from the top of the bowl, so it doesn't appear to be leaking there.  It leaks vacuum so badly I can't keep it running except at wide open throttle.  I've had it apart again and double checked for correct gaskets and I can't see anything wrong.  What do I do now? 

Title: Re: Vacuum leak at idle
Post by: comp on September 25, 2008, 02:11:26 PM

have you checked the base gasket ?

Title: Re: Vacuum leak at idle
Post by: omaha on June 08, 2009, 07:40:19 PM

You must have a big vacuum leak somewhere. Do you have power brakes. Maybe the power brake booster is leaking.
Need to try the usual tricks for finding vacuum leaks.

Title: Re: Vacuum leak at idle
Post by: Cliff Ruggles on June 09, 2009, 05:30:44 AM

Were any of the gaskets replaced during the repairs?  Sounds like one of them is not correct for the carburetor, or you have missed something somplace when hooking up all the hoses, etc.....Cliff

Title: Re: Vacuum leak at idle
Post by: Marx3 on June 09, 2009, 08:08:27 AM

I once had a sudden vacuum leak, and I just could not find it. After spraying and spraying with diesel-start, I finally found it at the base gasket, just underneath the vacuum port for the brakes.
It was leaking in an area of about 0.07" wide at the gasket. Very hard to find!