Series 60 DDEC VI Troubleshooting – Section 11.4 High Fuel Temperature Return

Section 11.4
High Fuel Temperature Return

To determine if high fuel temperature return is causing rough running or stalling, perform the following steps:‪

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

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).
   1. If the return fuel temperature is less than or equal to 60°C (140°F), check for improper injector calibration setting; refer to "11.5 Improper Injector Calibration Setting" .
   2. If the return fuel temperature is greater than 60°C (140°F), resolve the high fuel temperature; refer to "11.4.1 High fuel Temperature Resolution" .

Section 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 "11.4.1.1 Test the Engine with Replaced Oil Filters" .

Section 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 "11.4 High Fuel Temperature Return" 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).
   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 improper injector calibration setting; refer to "11.5 Improper Injector Calibration Setting" .