Quadrajet Problem Solving > Diagnose a Quadrajet carburetor problem

Cold start issue

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vickleford:
Just finished rebuilding a Quadrajet for my 82 Blazer which uses a hot air style choke. I'm trying to dial in the choke for 100% reliable cold starts, and I'm almost there.

For cold starts at about 40 degrees outside air temperature after sitting overnight, I depress the accelerator pedal once, release, and crank. It cranks right up then dies within 2 seconds. I depress the accelerator pedal again, release, crank, and it stays running.

This morning, at about 24 degrees air temperature after sitting overnight, I depressed the accelerator pedal once, released, crank, and it died within 2 seconds. I repeated this process 3 times before it kept running.

After depressing the accelerator pedal and before cranking, the choke flap stays engaged and I can push it open with very little resistance. If it were a rifle trigger, I'd compare it to 1-2 pounds pull.


* Does this sound like a choke setting issue?
* If so, does it make more sense to loosen the tension on choke spring to provide more oxygen?
Would have been lost without Cliff's book. Thanks for the publication.

429bbf:
i would say your to lean . you need to choke it a little harder. i prefer the electic choke it seems to be easier to set.also one less thing to mess with. if your coil is bad on the choke it would probably be cheaper in the long run to convert it. fwiw

429bbf:
one more thing ive seen the same thing happen when the bottom plus leak. did you test them on the overhaul?

vickleford:
Thanks! I'll tighten up that coil just a bit. I noticed it doesn't need much when tightening it, just increments in hairs' widths...

I think I tested the bottom plugs correctly. Sanity check me here: I rubbed a soapy water solution over the bottom well plugs and shot compressed air in one primary jet, then the other primary jet, then a secondary jet, then the other secondary jet while watching the soapy water solution to bubble over the bottom plugs. I saw no bubbles. Each shot of compressed air lasted about 5 seconds.

I also put a brand new fuel pump on, thinking that it may have been allowing fuel to leak back into the line. Didn't seem to affect anything.

Definitely interested in converting to electric choke, will research that some more.

429bbf:
thats the best way to test them. converting to electric is a piece of cake. remove your old choke coil housing,plug the small vacumn hole leading into the carb, (you can do this a couple different ways i like to tap it , i think a no.6 screw size install a allen head plug .)remove the gasket behind the old choke coil(because the new electric coil uses the housing for a ground }find a 12v  power source with the key on . plugin ,adjust, and enjoy.fwiw

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