Cliff's Quadrajet Parts and Rebuild Kits

Quadrajet Problem Solving => Diagnose a Quadrajet carburetor problem => Topic started by: IA57BA on October 05, 2011, 07:30:21 PM

Title: Idle Problems
Post by: IA57BA on October 05, 2011, 07:30:21 PM

I am trying to make a 7044213 carb work on a new GMPP 390hp 350. In order to make it idle I had to turn the idle adjustment screw in a long ways. In fact when I took the carb off I noticed that the throttle plate was above the fixed idle air bypass ports (vertical rectangular ports in front of barrel).

I assume this means the idle circuit is completely inoperative but when I opened up the carb I didn't see anything obviously broken or plugged. Is there a likely cause for this?
Thanks - JB

Title: Re: Idle Problems
Post by: Cliff Ruggles on October 16, 2011, 06:04:50 PM

The carburetor is an emission calibrated unit, and too lean at idle for the application.  It needs more idle fuel to get it back on the idle system.  Do you have one of our books?.....Cliff