Pressure Test: Mechanical
- Disconnect fuel line from carburetor. Connect line to a pressure gauge. Hold gauge about 16" (406 mm) above pump level. Pinch off fuel return line (if equipped).
- Start engine and allow to idle (using gasoline in carburetor bowl). Observe pressure gauge. Pressure should be about 4-7 psi (.28-.49 kg/cm2 ) for 4-cylinder and V6 engines, and about 6-9 psi (.42-.63 kg/cm2 ) for V8 engines.
- If pressure is too low, check fuel lines or gasoline tank filter for restrictions or leaks. If lines and filter are clear, pump is defective. If pressure is incorrect or varies greatly with the engine speed, replace the fuel pump.