Cliff's Quadrajet Parts and Rebuild Kits

Quadrajet Problem Solving => Diagnose a Quadrajet carburetor problem => Topic started by: vertbird on January 30, 2024, 11:51:27 AM

Title: Hot outside & bog on take off
Post by: vertbird on January 30, 2024, 11:51:27 AM

I have a Cliff Qjet that he built for me years ago.  I don't drive it much but I've started driving it more in the summer.  The car runs well in cooler temps (<75 degrees outside) but once the ambient temp hits 80 and humidity is up, the car is a slug off the line.  Is the secondary spring set too light for hot weather or do you think it's something else?

Title: Re: Hot outside & bog on take off
Post by: Cliff Ruggles on January 31, 2024, 04:43:25 AM

What is the carburetor part number?

Application, engine/drivetrain/vehicle specs?....

Title: Re: Hot outside & bog on take off
Post by: vertbird on January 31, 2024, 12:03:02 PM

Hi Cliff,
Thanks for responding, the carb is #17056274.  It's on a 76 Trans am 400 with TH350 & 2.73 rear gear.  6x-8 heads that Kauffman reworked but still at 7.9:1 running the crower 60240 cam.

Title: Re: Hot outside & bog on take off
Post by: Cliff Ruggles on February 01, 2024, 05:56:03 AM

Those are excellent units, same carb I used on my own engines for over 40 years and never had a single issue with it.

May be heat related but keep in mind that a "low" compression 400 build with a 210/222 @ . 050" cam plus 2.56 gears isn't going to be much faster off the line than my garden tractor anyhow.  Hot/humid temps raise the DA and you loose a LOT more power.

If it's developing a hesitation/stumble or bog going quickly to full throttle you might want try tightening up the spring for the air flap shaft just a tad to see if it helps.......

Title: Re: Hot outside & bog on take off
Post by: vertbird on February 01, 2024, 07:45:55 AM

Thank you Cliff !

Title: Re: Hot outside & bog on take off
Post by: Kenth on February 01, 2024, 07:48:21 AM

The DB secondary rods won´t help much, use a set of CV/AU/CK instead.