Cliff's Quadrajet Parts and Rebuild Kits

Quadrajet Problem Solving => Diagnose a Quadrajet carburetor problem => Topic started by: lakedrifter on December 23, 2015, 02:30:26 PM

Title: Quadrajet Hard Starts
Post by: lakedrifter on December 23, 2015, 02:30:26 PM
I know you guys have seen this issue a time or two but I need to pick some brains anyway.

I'm aware of the hard starts after sitting for awhile and the well plugs leaking and letting the fuel bowl go dry, but I don't believe that is my case.  The last time I had my carb apart I drilled and tapped the well plugs, per some other post I had seen.

The issue I am having is when trying to start 30 minutes or so after I have shut the engine off.  You have to crank and hold the peddle down and then it will fire up.

If you let it set for a couple hours, it starts back up just fine.  No peddle required.

Any info is always appreciated.

Heath
Title: Re: Quadrajet Hard Starts
Post by: Cliff Ruggles on December 25, 2015, 03:50:26 AM
Certainly the symptoms of some fuel leaking into the intake after shut-down.  Did you pressure test the bottom plugs after the repair?.....Cliff
Title: Re: Quadrajet Hard Starts
Post by: 77cruiser on December 25, 2015, 04:46:43 AM
Float level? Possible that the inlet needle & seat are leaking.
Title: Re: Quadrajet Hard Starts
Post by: lakedrifter on December 25, 2015, 06:55:08 AM
No, I had not heard of pressure testing the float bowl?  Is there an easy way to do that?

I'll have it off today again so, i will check the float level again.

Title: Re: Quadrajet Hard Starts
Post by: lakedrifter on December 25, 2015, 10:51:43 AM
One of the other problems i have had is poor warm ups.   I havent been able to quite dial it in.  While working on the van today i noticed that my efe canister did not close when i started the van earlier.  I tested the efe with a vacuum pump and it operates correctly.  So i started back tracking and figured out it works off of ported vacuum.   With the TPVS now in question, I tested the vacuum at the vacuum advance and found less than -10lbs ov vacuum.  Does anyone know what the vacuum should be at the advance on a cold start?  Im wondering if the TPVS is out and maybe stimulating some of what i percieve to be carb problems?
Title: Re: Quadrajet Hard Starts
Post by: lakedrifter on December 26, 2015, 06:12:40 AM
I figured it out.  It was a vacuum leak!
Title: Re: Quadrajet Hard Starts
Post by: Cliff Ruggles on December 30, 2015, 04:45:06 AM
Good news!