BELT-SERPENTINE 2500678 - Caterpillar

Low Power/Poor Fuel Consumption Troubleshooting With A Dynamometer
1. Interview the customer to determine the nature of the complaint, engine and vehicle configuration, application and operating conditions. The Performance Check List, Form No. SEHS8647, is available to record this information.2. Consider effect of non-engine related factors on the complaint. Vehicle efficiency, driver efficiency and operating conditions can have a dramatic effect on vehicle performance. For a complete explanation of each of these non-engine related factors, refer to the Truck Performance Diagnostic Guide, Form No. SEBD0808.3. Is maintenance tune-up due? If so, consider the effect and perform before proceeding further with diagnosis of the performance complaint.4. Electronics; Logged Fault Codes. Check the electronic system for logged fault codes. Examine for faults that are indicated by; (1) diagnostic lamp on vehicle dash and (2) fault screen on ECAP. Determine if correlation exists between customer complaint and possible problems as related to fault codes. Refer to the "Troubleshooting Diagnostic Codes" section in Electronic Troubleshooting, 3176 Diesel Truck Engine, Form No. SENR5112. Repair as required if a fault is detected. Consider the effect of any repair on the performance complaint before proceeding with step 5.5. Evaluate the impact of customer specified parameters on the complaint (include check of the personality module part no. and rating within a family). Verify that all parameters are correctly programmed (including pulses per mile) and the driver understands their effect on vehicle operation. Re-programming may be required. Refer to the "Programming 3176 Parameters" section in the Electronic Troubleshooting, 3176 Diesel Truck Engine, Form No. SENR5112.6. Check throttle position sensor (% duty cycle) adjustment using the ECAP or the DDT service tools. Throttle position sensor/duty cycle is displayed on the "Monitor/Calibrate Sensors"-"Monitor Throttle Position Sensor Signal" screen. Refer to Engine Test Procedure Number P-303 in Electronic Troubleshooting, 3176 Diesel Truck Engine, Form No. SENR5112. Adjust or repair as required.7. If the vehicle is equipped with a fuel heater, it should be turned "OFF" (automatically or manually) during moderate to warm weather operation. Fuel temperatures above 30°C (85°F) will reduce maximum potential horsepower but have little effect on fuel economy (refer to the Truck Performance Diagnostic Guide, Form No. SEBD0808, for further details).8. Measure fuel API. Lighter blended fuels will reduce maximum potential horsepower and decrease fuel economy (refer to the Truck Performance Diagnostic Guide, Form No. SEBD0808, for further details).9. Measure the fuel transfer pump pressure at rated engine rpm. The 1U5470 Engine Pressure Group can be used to measure the fuel transfer pump pressure. The 1U5470 Engine Pressure Group has a gauge to read fuel pressure. Special Instruction, Form No. SEHS8907 is with the tool group and gives information for its use. The ECAP or the DDT can also be used to check the fuel transfer pump pressure.If the fuel transfer pump pressure is below 445 kPa (65 psi) at rated rpm, check for: * Restrictions in the low pressure fuel system (plugged fuel filter, collapsed hoses, etc).* Air in the fuel.* Fuel transfer pump wear or damage.