Cliff's Quadrajet Parts and Rebuild Kits

Quadrajet Problem Solving => Diagnose a Quadrajet carburetor problem => Topic started by: Nhrajeff on July 12, 2015, 04:04:22 AM

Title: No idle adjustability. Very lean, at least at idle. Stumbles off idle.
Post by: Nhrajeff on July 12, 2015, 04:04:22 AM

Just finished a 17059253, on a 1979 T/A. There is no change in idle, regardless of mixture screw position. If I cup the air horn, idle improves, and doesn't surge up and down. Wondering if I grossly overlooked something. Any suggestions on what to look at first? Also what float level do you suggest?

Title: Re: No idle adjustability. Very lean, at least at idle. Stumbles off idle.
Post by: Cliff Ruggles on July 14, 2015, 04:51:21 AM

Did you use one of our kits in it?.....Cliff

Title: Re: No idle adjustability. Very lean, at least at idle. Stumbles off idle.
Post by: Nhrajeff on July 18, 2015, 04:58:28 AM

I bought everything from you. I drove out there in March. You drilled the idle tubes, 038. I added bypass air, .100, drilled out idle screw openings to .090 I believe. Air bleeds are .070. It's a 79 403, 10.5:1, camshaft is 236/240, in at 104, lift is .553/.544, LSA is 110 I believe. I found out that I had the APT screwed in all the way, so I moved it out 2.5 turns. How do I adjust the APT, or is there a baseline setting? I have an idle circuit now, but would like to have the APT where it needs to be.

Title: Re: No idle adjustability. Very lean, at least at idle. Stumbles off idle.
Post by: Cliff Ruggles on July 19, 2015, 09:41:32 AM

It will help to open up the DCR's to at least .055" for that cam, .059" would be even better.

I'd set the APT at 3.5 turns for initial testing, then raise it up if/as needed to add some fuel for "normal" driving....Cliff