To determine if a faulty fuel injector is causing the cylinder to misfire, perform the following steps:
- Install DDL adaptor to the data cable and plug the adaptor into the DDL connector in the vehicle; refer to OEM guidelines.
- Start the engine.
- >From the DDEC III/IV Select Menu, scroll to select ENGINE and press the ENTER key.
- Scroll to FUEL INJECTOR INFO (CUTOUT) and press the ENTER key.
- Scroll to select NEW TEST and press the ENTER key.
- Scroll to select RPM SETTING FOR CCO TEST NORMAL and scroll to select 1000 and press the ENTER key.
- Scroll to select AUTO and press the ENTER key. Wait for END OF TEST.Note: If an injector cannot be cutout, you will see an ERROR message. Press FUNC to exit the cylinder cutout function, press the FUNC key.
- 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 degrees of the NO CUTOUT PULSE WIDTH, by comparing the CUTOUT PULSE WIDTH values to the NO CUTOUT PULSE WIDTH values.
- If any CUTOUT PULSE WIDTH values are within 0.2 degrees of the NO CUTOUT PULSE WIDTH, shut down the engine and refer to section .
- If any CUTOUT PULSE WIDTH values are not within 0.2 degrees of the NO CUTOUT PULSE WIDTH, shut down the engine.
Faulty Fuel Injector Repair
Perform the following steps for faulty fuel injector assembly(s):
- Remove and replace injector assembly(s) whose values are within 0.2 degrees of the NO CUTOUT PULSE WIDTH;
- Verify replaced injector assembly(s), .
Verification of Repair for Faulty Fuel Injector
Perform the following steps to determine if the replaced fuel injector(s) resolved the misfiring cylinder condition:
- Refer to section for the exhaust caution before preceeding. Start the engine.
- Run the engine speed up to the occurrence of the misfiring.
- Listen for misfiring cylinder.
- If the engine is not misfiring, shut down the engine. No further troubleshooting is required.
- If the engine is misfiring, shut down the engine and check for a faulty electronic control module (ECM);