To determine if high fuel temperature return is causing rough running or stalling, perform the
following steps:
1. Connect to DDDL 7.0.
2. Start and run the engine.
3. 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).
[a] If the return fuel temperature is less than or equal to 60°C (140°F), check for
improper injector calibration setting; refer to section 11.5.
[b] If the return fuel temperature is greater than 60°C (140°F), resolve the high fuel
temperature; refer to section 11.4.1.
11.4.1
High fuel Temperature Resolution
Perform the following steps to resolve high fuel temperature:
1. Remove and replace fuel filter(s); refer to appropriate service manual, fuel system chapter.
2. Inspect check valve for any restricted fitting; refer to appropriate service manual, fuel
system chapter.
3. Replace both the restrictive fitting or check valve; refer to appropriate service manual,
fuel system chapter.
4. Verify fuel filter(s) replacement; refer to section 11.4.1.1.
11.4.1.1
Test the Engine with Replaced Oil Filters
Perform the following steps to determine if the replaced oil filter(s) resolved the rough running
or stalling condition:
1. Refer to section11.4 for exhaust caution before proceeding. Start and run the engine.
2. Run the engine through its operating range with no-load for approximately 5 minutes,
allowing the engine coolant to reach normal operating range, 88-96°C (190-210°F).
[a] If the engine is not running rough or stalling, no further troubleshooting is required.
Shut down the engine.
[b] If the engine is running rough or stalling, shut down the engine. Check for improper
injector calibration setting; refer to section 11.5.
