To determine if high fuel temperature return is causing lack of power, perform the following steps:
1. Test for high fuel temperature return.
2. Analyze the high fuel temperature test results.
[a] If the return fuel temperature is less than or equal to 54°C (130°F), check for air
cleaner restriction; refer to section 12.6.
[b] If the return fuel temperature is greater than 54°C (130°F), resolve the high fuel
temperature return condition; refer to section 12.5.1.
12.5.1
High Fuel Temperature Resolution
Perform the following steps to resolve high fuel temperature return:
1. Remove and replace fuel filter(s); refer to Series 60 Service manual (6SE2007), fuel
system chapter.
2. Inspect the combination check valve/regulator, replace if necessary; refer to Series 60
Service manual (6SE2007), fuel system chapter.
3. If equipped with a fuel cooler, refer to OEM for inspection guidelines.
4. Verify high fuel temperature repair; refer to section 12.5.1.1.
12.5.1.1
Test the Engine with Resolved High Fuel Temperature
Perform the following steps to determine if high fuel temperature repairs resolved lack of power
condition:
1. Start and run the engine.
2. Test drive the vehicle to ensure lack of power has been resolved.
[a] If lack of power did not occur during the test drive, no further troubleshooting is
required. Shut down the engine.
[b] If lack of power occurred during the test drive, shut down the engine. Check for a
restricted air cleaner element; refer to section 12.6.
