Fuel Pressure: Testing and Inspection

Fuel system pressure must be released any time a fuel line is to be disconnected.

1. Disconnect 5/16 inch fuel supply hose from engine fuel line assembly, then connect fuel pressure gauge C-3292 and hose adapter C-4749 or equivalent between fuel supply hose and engine fuel line assembly.

2. Using ATM tester C-4805, place ignition switch in Run position and depress ATM button to activate fuel pump. Gauge should indicate 46 - 50 psi pressure. If pressure is as specified, remove gauge and adapter.

3. If fuel pressure is below 46 psi, install tester in fuel supply line, between fuel tank and fuel filter. Repeat test. If pressure is 5 psi higher than previously recorded pressure, replace fuel filter. If pressure does not increase, gently squeeze fuel return hose. If pressure now increases, replace pressure regulator. If fuel pressure still does not increase, either the fuel pump is defective or the filter sock is obstructed

4. If fuel pressure exceeds 50 psi, remove fuel return hose from fuel return line. Install suitable length of hose to fuel return line and place open end of hose into a clean container. Repeat test. If pressure is now within specifications, check fuel return line for restrictions. If fuel pressure is not as specified, replace fuel regulator.