Quadrajet Problem Solving > Diagnose a Quadrajet carburetor problem

Car will not accelerate under load, sometimes backfires

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kirkp:
Car is a 83 Hurst Olds stock 307.  Bought the car and it ran fine when I bought it other than it wouldn't idle very well.  It sat in my garage for a few months before I had time to mess with it.  I tried to turn the idle screw up a little and took the car for a ride and then it wouldn't accelerate.  About 2000 rpm it would fall on its face no matter how hard or easy I pressed the gas.  If I stayed in the pedal it would sometimes backfire.  Seemed to me like it was running out of fuel.  Thought I would start with some easy things and went with plugs, wires, distributor cap and rotor, plus changed out all the vacuum lines.  Still exactly the same.  Ordered a carb kit from Cliff and went through the carb.  I have rebuilt other quadrajets but never a CCC.  The idle mixture screws were way off of the starting point of 4.5 turns out.  The right side was 2.5 turns out and the left side was 1/4 turn out.  I reset those to the 4.5 turns out and the idle is nice now.  The acceleration problem is still the same.  Does anyone have some suggestions?  I don't know where to go next.

77cruiser:
If the mechanical advance is rusted & sticking it might be the cause. Did you pull the cap & rotor to check it?

Cliff Ruggles:
Disconnect the plug to the M/C solenoid and see if things improve.  If so the solenoid isn't functioning properly and causing lean condition......Cliff

kirkp:
Cliff, I will try that. One thing I noticed while rebuilding the carb is the stop on the air horn for that M/C solenoid was threaded out quite a way.  I looked at some videos of other people tearing down these carbs and theirs did not look that far out. I didn't move it because I didn't know what a starting point setting was for it. I moved it a little one way and then back and it turned really easy.  I'm not sure if this could have moved when trailering the car home.

kirkp:
Here is a picture of the stop. 

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