How-to: Testing Fuel Systems with Schrader Valve Test Ports

The picture illustrates fuel testing systems with existing test ports (Schrader Valves).

1. Relieve fuel system pressure before connecting the tester, please refer your car’s service manual for procedures.

2. Check whether the ignition is OFF.

3. Remove the protective cap of the fuel system’s test valve or port.

4. Connect the tester to the vehicle’s fuel system. For Ford and some Chryslers you need to install the Ford port adapter on the throttle body or fuel rail test port, Finger Tight Only, then connect the gauge hose to the adapter. For GM, connect the gauge directly to test port, Finger Tight Only. Please see the figure above.

5. Folow on ‘Key On Engine Off Test”.