Fuel pressure
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Le Mans Master
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From: Richmond Kentucky
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Fuel pressure
What is the proper fuel pressure for a carbureted big block Chevy street engine (pressure at the carb)? System has a Holley electric fuel pump, 750 carb, in-line adjustable regulator and a pressure gauge, newly installed, reads 11 psi with pump on and engine off. I adjusted the regulator to lower the pressure but to no avail. Does engine have to be running when adjustments are made?
Pro
Joined: Oct 2004
Posts: 573
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From: Stafford VA
You set fuel pressure with flow at idle, either through the carb while the engine is running or through a flow gauge that simulates a carb. If your carb is in good condition, anything under 9psi shouldn't overflow the bowls and above 4.5psi is enough to keep the motor fed.
11psi is too high but until you get flow through the regulator, you won't have a truly accurate measurement.
11psi is too high but until you get flow through the regulator, you won't have a truly accurate measurement.
