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Mike S.
Mike S., Classic Car Mechanic
Category: Classic Car
Satisfied Customers: 6702
Experience:  A.S.E. certified with 25+ years experience.
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Chevrolet El Camino: I have a 1972 El Camino with a 402 and

Customer Question

I have a 1972 El Camino with a 402 and a TH400 automatic. I have removed the air conditioner and installed vintage air, removed intake manifold and carburetor, installed Edelbrock manifold and 800 cfm carburetor. I have also installed a new thermostat. Now, I'm having problems with overheating and running properly. No matter where I set the timing, it backfires through the carburetor and now the idle won't go above 500 rpm.
Any ideas?
Submitted: 5 months ago.
Category: Classic Car
Expert:  Mike S. replied 5 months ago.
It sounds to me as though the choke is set too lean. Try adjusting the choke more rich or closed. Then once it warms up, thermostat opens, without overheating adjust the idle/air mixtures and base idle.
Expert:  Mike S. replied 5 months ago.
I would also be sure you don't have a vacuum leak, such as a vacuum hose left off that old ac system. that includes any vacuum hoses that ran into the firewall for the ac controls or vacuum actuators on the box under the dash.

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