75 GMC 250cid won't idle

1975 GMC
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RADARMAX
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I have a 75 GMC 3/4 ton 4x4 4 speed. It has a 250 cid that is not the original engine. This engine has the integral head. It has a Rochester Vara Jet II carb. The head gasket was replaced due to leaking and the carb was rebuilt. Timing checks ok. New fuel pump, fuel filter and lines It will not idle, as long as you keep it reved up to about 1200 rpm's or so it sounds great but when it idles down it will die. Every once in awhile it will stay running but idles rough. If, when adjusting the rockers if they were tightened to much would that cause this problem?
All so the wire that goes to the choke, is it hot only when the starter is engaged?
Any help will be appreciated.
Thank you.
Dec 16, 2006 at 10:02 AM
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GARFIELD
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First what is the lowest RPM that you can get it to idle at? Second have you checked the vacuum on the engine while it is running? As for the choke, I am assuming you are referring to an electric choke, my wiring on my nova is hot anytime the car ignition is on.
Dec 23, 2006 at 6:40 AM