This condition will exist if there is an external or internal leak of the low pressure fuel system. Tool J-48710 is required for this testing.
Test as follows:
- Remove the fuel feed and return lines from the fuel filter module.
- Install J-48710 fuel pressure test kit onto the module.
- Ensure the shutoff valve is in the OFF position.
- Turn regulator counter-clockwise until it stops. The regulator is now set to zero pressure.
- Turn the shutoff valve to the ON position.
- Once the system pressure has reached 30 psi, turn the shutoff valve to the OFF position.
- The system pressure should not drop over 10 minutes.Note: The fuel cooler and feed line for the amplifier circuit is located behind the fuel filter module. Ensure this area is not overlooked.
Note: When removing J-4870, point the nozzle away from your body and into a container.
- If the system pressure drops off over 10 minutes, use a soapy solution and spray all connectors, fittings, and braided hoses.
- If no leaks are found, go to next step.
- If leaks are found, repair as necessary.
- Remove oil fill cap and listen for internal air leaks.
- If internal leaks are found, remove the rocker cover to locate which injector seal ring is leaking.
- If no internal leaks are located, go to next steps
- Install cooling system pressure testing tool.
- If cooling system pressure increases, replace fuel cooler located behind fuel filter module.
- If cooling system pressure does not increase, no problem found.