Quadrajet Problem Solving > Dialing in your rebuilt Quadrajet carburetor

Qjet going lean at part throttle acceloration

(1/3) > >>

mertz28:
I have been doing some adjustment on my carb.  I tried to get a little more vacuum so I adjusted the idle mixture screws out and got another 1".  Problem is it now pops out the exhaust when I let off the gas.  I attached my wideband A/F gauge and it is rich at idle which I can fix.  After a test drive I noticed a lean condition when I accelerate at part throttle.  This goes away when I apply more throttle and then it really moves.  The A/F gauge reads lean under those condition and 12.5 when it starts to pick up the acceleration.  It has always been slow to pick up speed under 45mph.  When I got the carb back from Cliff, I only adjust the mixture screws a little to get max vacuum.  How can I improve the slow speed bog?  A/F seems to be fine everywhere else.  I believe the timing is at 14 initial and 36 total.  I am on manifold vacuum.  Engine runs great except the slow start and low speeds.

Cliff Ruggles:
What is the carburetor number, and what is it being used on?....Cliff

mertz28:
It is a 17057213 that you built for me.  It is on a 1972 Chevy C20 pickup with 350 and 350 trans.  Edelbrock manifold, headers, MSD ignition, and 1" Hambuger spacer.

77cruiser:
How lean does it go? Might have to adjust the APT raise the rods.

mertz28:
It goes to 14.7 and somewhat leaner.  I have a bar gauge so I don't get exact read outs.  It goes to the lean side of 14.7.  I thought about the APT and Cliff set it up so it could be adjusted.  So I would want to pull them up a little to see if that helps.  When they are modified do they get a philips screw or the stock one?

Navigation

[0] Message Index

[#] Next page