DD15 Insufficient Fuel Flow Troubleshooting

Check as follows:‪

1. Does the engine start and run?
   1. If yes, check for loose connections, kinked fuel lines, or issues related to the fuel tank. Repair or replace as necessary.
   2. If no, go to next step.
2. Watch the fuel from the J-48708 tank to the inlet of the fuel filter module. Is fuel reaching the fuel filter module?
   1. If yes, go to step 4 .
   2. If no, go to the next step.
3. Check the following components
   1. Check for kinked LPP inlet and outlet lines between filter module and pump.
   2. Check for loose connections allowing large amounts of air to enter the fuel system
   3. Remove and inspect the low pressure pump for wear or broken oldham connection.
4. Watch the return fuel going to the tank.
5. Are there large amounts return fuel as soon as the engine cranks?
   1. If yes, check the three filter caps for proper torque and seating. If this is OK, go to step 6 .
   2. If no, check the air vents at the top of the coalescer and final filters for blockage. Replace filters if needed.
6. Remove prefilter, coalescer, and final filters. Check for damaged or missing seals at the bottom of the filters.
7. If all steps have been followed and a “No Start” condition still exists, replace high pressure pump (for customer demo the low and high pressure pump will be serviced as an assembly).
   

   ENGINE EXHAUST ‪
   To avoid injury from inhaling engine exhaust, always operate the engine in a well-ventilated area. Engine exhaust is toxic.‪

8. Start and run the engine.
9. Run the engine at idle with a no-load for approximately 5 minutes, allowing the engine coolant to reach normal operating range, 88-96°C (190-210°F).
   1. If the engine is not running rough or stalling, no further troubleshooting is required. Shut down the engine.
   2. If the engine is running rough or stalling, shut down the engine. Check for high fuel temperature return; refer to “10.8 High Fuel Temperature Return” .