Series 50 – Section 16.5 Faulty Fuel Injector

Section 16.5
Faulty Fuel Injector

To determine if a faulty fuel injector is causing the cylinder to misfire, perform the following steps: ‪

1. Install DDL adaptor to the data cable and plug the adaptor into the DDL connector in the vehicle; refer to OEM guidelines.
2. Start the engine.
3. From the DDEC III Select Menu, scroll to select ENGINE and press the ENTER key.
4. Scroll to FUEL INJECTOR INFO (CUTOUT) and press the ENTER key.
5. Scroll to select NEW TEST and press the ENTER key.
6. Scroll to select RPM SETTING FOR CCO TEST NORMAL and scroll to select 1000 and press the ENTER key.
7. Scroll to select AUTO and press the ENTER key. Wait for END OF TEST.

   Note: If an injector cannot be cutout, an ERROR message will appear. Press FUNC to exit the cylinder cutout function, press the FUNC key.

8. Scroll the list to review the results of the cylinder cutout test. To find suspect injectors, look for a cylinder with a value that is within 0.2° of the NO CUTOUT PULSE WIDTH, by comparing the CUTOUT PULSE WIDTH values to the NO CUTOUT PULSE WIDTH values.
   1. If any CUTOUT PULSE WIDTH values are within 0.2° of the NO CUTOUT PULSE WIDTH, shut down the engine and refer to "16.5.1 Faulty Fuel Injector Repair" .
   2. If any CUTOUT PULSE WIDTH values are not within 0.2° of the NO CUTOUT PULSE WIDTH, shut down the engine and refer to "16.6 Faulty Electronic Control Module" .

Section 16.5.1
Faulty Fuel Injector Repair

Perform the following steps for faulty fuel injector assembly(s):‪

1. Remove and replace injector assembly(s) whose values are within 0.2° of the NO CUTOUT PULSE WIDTH; refer to "2.3.2 Removal of Unit Injector" .
2. Verify replaced injector assembly(s), refer to "16.5.1.1 Verification of Repair for Faulty Fuel Injector" .

Section 16.5.1.1
Verification of Repair for Faulty Fuel Injector

Perform the following to determine if the replaced fuel injector(s) resolved the misfiring cylinder condition:‪

1. Start the engine.
2. Run the engine speed up to the occurrence of the misfiring.
3. Listen for misfiring cylinder.
   1. If the engine is not misfiring, shut down the engine. No further troubleshooting is required.
   2. If the engine is misfiring, shut down the engine and check for a faulty electronic control module (ECM); refer to "16.7 Worn or Damaged Valve or Cylinder Kit" .