407914-2000 ZEXEL 9 443 612 681 BOSCH CONTROL UNIT 9443612681 4079142000

Recommended Procedure With Chassis Dynamometer
Possible Causes/Corrections
Minor Operating Faults/To help identify a problem before a more involved troubleshooting procedure is started, follow the procedure given in the PRIMARY ENGINE CHECKS section. Fuel Ratio Control Out of Adjustment or Bad/Follow the procedure in the Testing and Adjusting section of this Service Manual. Check Engine Performance/Do a Power Analysis Report (PAR), Level II, to check engine performance. See Special Instruction, Form No. SEHS8025 and SEHS7886 for the tooling and procedures to use. Be sure to make a record of the temperatures for inlet air, fuel (at filter base), lubricating oil and coolant. Make the necessary adjustments or repairs to the engine if needed.At this point, the governor fuel settings should be verified. See the Testing and Adjusting section of this Service Manual for the necessary procedures. Also, refer back to the information learned earlier (see OWNER/OPERATOR INPUT section) about the truck specifications and application and judge whether or not the engine is performing as expected or customer expectation is realistic.Recommended Procedure Without Chassis Dynamometer
Possible Causes/Corrections
Minor Operating Faults/To help identify a problem before a more involved troubleshooting procedure is started, follow the procedure given in the PRIMARY ENGINE CHECKS section. Fuel Ratio Control Out of Adjustment or Bad/Follow the procedure in the Testing and Adjusting section of this Service Manual. Fuel Injection Timing Not Correct/Follow the procedures in the Testing and Adjusting section of this Service Manual. Check Engine Performance/Install the tooling and follow the procedure given in the ROAD TEST section.At this point, the governor fuel settings should be verified. See the Testing and Adjusting section of this Service Manual for the necessary procedures. Also, refer back to the information learned earlier (see OWNER/OPERATOR INPUT section) about the truck specifications and application and judge whether or not the engine is performing as expected or customer expectation is realistic.