Question about 1978 Chevrolet C1500

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350 chevy with elebrook carb will not idle below 2500 can you help? just rebuilt this carb. every thing went good all settings done by the book. very clean inside all jets cleaned or replaced. re check floats 7/16 on top and 15/16 on drop. I have re checked all vac. lines all is good to this point. with all the stop screws all the way out and linkage is free with good movement. the front two idle screws set to 1 1/2 turns out. the engine will start great but will not come under 2500 rpm timing is set at 12 deg. any ideas?

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  • Zaraki Oct 24, 2010

    Was the correct carburetor base gasket used for that carburetor, (there are a few different ones) and was it installed correctly? (if the carburetor base gasket is installed upside-down or it is the wrong base gasket then there will be a large vacuum leak and the engine might not get enough fuel to be able to hold an idle when warmed up or actually when the choke kicks down off of the high idle)



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Manually operate the choke mechanism and watch to make sure it fully releases. Quite often mistakes can occur when putting the pieces back together and it won't fully release off fast idle.Are you absolutely positive that you didn't forget an o- ring or ball when you put the carb back together? Is there any chance there is a gasket upside down? Could the power valve be in wrong? These types of things could create that problem, there is too much gas going through your idle circuit.What happens when you turn in the idle screws? Are you sure about the timing? I don't have specs for a 1/2 ton but all the specs in my Chilton give me 6 degrees in California and 8 degrees everywhere else. These numbers cover all models of cars for a 1978 350. Hope this helps.

Posted on Oct 24, 2010


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