Quadrajet Problem Solving > Diagnose a Quadrajet carburetor problem

Confirm these specs, please. Cadillac 500

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Marx3:
I have a 17056230 on a stock 500.
I recently rebuild the carb and modified the main system with great results.
On the idle circuit I shot a bit over the target.
.097 bypass
.058 DCR
.037
.090 mixture screw holes.
With this set I couldn't bring the idle lower than 8-900, unless I backed down the timing a lot.
I finally realized the idle circuit was way too generous.

Here is the new setup:
.051 bypass
.046 DCR
.036 tubes
.090 holes.
Needless to say, I can now bring the idle down as much as I want until I kill the engine, but I am swing erratical idle.
For example: engine is idling at 600 and I blip the throttle, revving it to 2500-3000 rpm for a split second.
Coming back down to idle, the engine tends to want to settle a different rpm than before.
Than I back down the idle and flip the throttle again. Coming down now, the idle is too low suddenly.
The car needs brake work, so I chat take it for a spin and get some realistic action from the the carb.
These adjustments are made in a warm greenhouse. At the end I had the air horn off and confirmed the idle was boiling slightly.
Are these specs off for a stick low compression 500 or what?
I feel I am starting myself blind here.
I have successfully built and calibrated lots of Qjet over the years, but this one is giving me the fits.

429bbf:
just a thought , did you take the distributer out of the equation . i had one act similar and i had a set of sticking weights drive me crazy . after i took the carb apart 3 times i finally figured it out. hah

Marx3:
Yes the distributor is serviced and in good working condition.
Timing is bumped up a bit and using ported vacum.
What problem did you think stuck weights would give, in this case?
Erratic idle?

429bbf:
it did for me .the way i figured it out was by driving it .if i just puts around say less than 2000rpm everything was fine . once i reved it up 35to4000 the problem started again i blamed the carb of course . finally they stuck and when i rechecked timing i was a mile off. fixed it and been running great. fwiw

Marx3:
I hear ya. Better re-check. Better than sorry.
Do you have any opinion on these idle specs for a stock huge engine?

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