Cliff's Quadrajet Parts and Rebuild Kits

Quadrajet Problem Solving => Diagnose a Quadrajet carburetor problem => Topic started by: tw9999 on March 11, 2015, 10:44:52 AM

Title: Vacuum testing needle/seat
Post by: tw9999 on March 11, 2015, 10:44:52 AM

Cliff,
In your book you recommend vacuum testing the needle/seat before installing and would like to know if mine is good.  I attached a hose to the threaded portion of the seat with a hose clamp and the other to my mighty vac.  With the needle installed, this setup will only hold vacuum when I apply a slight pressure to the needle with my finger.  Is this normal?  The reason I checked the vacuum is because the carb exhibits signs of flooding.  I have lowered the float level to 5/16 so I know the level is not the problem.  The carb number is 7029207.

Thanks
Tim

Title: Re: Vacuum testing needle/seat
Post by: carmantx on March 11, 2015, 08:30:02 PM

Did you get your parts from Cliff?

Title: Re: Vacuum testing needle/seat
Post by: tw9999 on March 12, 2015, 11:04:29 AM

I should have mentioned that I just rebuilt the carb with a kit I got from Cliff.  After rebuilding I set the float at 1/4 inch, but had to set it lower because fuel was soaking through the air horn gasket along with a strong fuel smell.  Fuel no longer soaks through the air horn gasket, but 5/16 is a little low and I'm thinking the needle is requiring more pressure than normal to stop the incoming fuel.  I'm running a stock mechanical fuel pump,  Everything else is working well, idle, part throttle, WOT, but the strong fuel smell is still there.

Title: Re: Vacuum testing needle/seat
Post by: tw9999 on March 12, 2015, 11:05:41 AM

...also hard hot starting

Title: Re: Vacuum testing needle/seat
Post by: carmantx on March 12, 2015, 11:07:51 AM

take the clip off of the needle and let the needle rest in the seat on it's own.  It may be causing a little bind and not letting it close.

Title: Re: Vacuum testing needle/seat
Post by: tw9999 on March 12, 2015, 11:39:56 AM

Ok, I'll give it a try.  Thanks