- Remove the fuel intake hose from the throttle body and connect fuel system pressure testers C-3292, and C-4749, or equivalent, between the fuel filter hose and the throttle body.
- Start the engine and read the gauge. Pressure should be 14.5 psi (100 kPa).
ATM tester C-4805 or equivalent can be used. With the ignition in RUN, depress the ATM button. This activates the fuel pump and pressurizes the system
If the fuel pressure is below specifications:
- Install the tester between the fuel filter hose and the fuel line.
- Start the engine. If the pressure is now correct, replace the fuel filter. If no change is observed, gently squeeze the return hose. If the pressure increases, replace the pressure regulator. If no change is observed, the problem is either a plugged pump filter sock or a defective fuel pump.
If the pressure is above specifications:
- Remove the fuel return hose from the throttle body. Connect a substitute hose and place the other end of the hose in a clean container.
- Start the engine. If the pressure is now correct, check for a restricted fuel return line. If no change is observed, replace the fuel regulator.