Pressure Test (Mechanical)
- Disconnect fuel line from carburetor. Connect line to a pressure gauge.
- Hold gauge about 16" above pump level. Pinch off fuel return line (if equipped).
- Start engine and allow to idle (using gas in carburetor bowl).
- Observe pressure gauge. Pressure should be about 4-7 psi (.28-.49 kg/cm2
) for 4 and 6 cylinder engines, and about 6-9 psi (.42-.63 kg/cm2
) for V8 engines.NOTE: See appropriate article in TUNE-UP Section for exact pump pressure and volume specifications.
- Replace pump if pressure is too high or low, or if pressure varies greatly with the engine speed.