To determine if a plugged fuel filters is causing starting difficulty, perform the following steps:
1. Disconnect the fuel line return hose from the fitting located at the fuel tank.
2. Place the opened end of fuel line into a five gallon container.
3. Start the engine.
4. Run the engine at 1000 rpm.
5. Clock fuel rate for one minute.
6. Measure the amount of fuel flowed into the container.
[a] If the fuel flow is greater than 3.8 L/min (1 gal/min), check for air in fuel;
refer to section 4.10.
[b] If the fuel flow is less than 3.8 L/min (1 gal/min), replace the fuel filters;
refer to section 4.8.1.
Plugged Fuel Filter(s) Replacement
Perform the following steps to replace fuel filter(s):
1. Replace the fuel filter; refer to the appropriate service manual, preventive maintenance chapter.
2. Test the engine to determine if starting has been improved; refer to section 220.127.116.11.
Test Engine with Replaced Fuel Filters
To determine if the replaced fuel filters resolved the starting difficulty, refer to section 4.8 for the exhaust caution before proceeding. Attempt to start and run the engine.
1. If the engine starts and runs, no further troubleshooting is required. Shut down the engine.
2. If the engine fails to start and run, check the fuel pump; refer to section 4.9.