21170733 Volvo.Penta Connecting pipe

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Table 1
Troubleshooting Test Steps Values Results
1. Check Derate or High Altitude Operation
A. Connect Caterpillar Electronic Technician (ET) and check for logged events that derate engine power. An engine derate indicator will appear on Cat ET if an active engine derate is occurring.
Note: The following conditions may cause an engine derate that is not annunciated to the operator.
B. The Electronic Control Module (ECM) monitors the following parameters in order to calculate a value for the exhaust temperature of the engine:
- Intake manifold air temperature
- Turbocharger compressor inlet pressures
- Engine speed
Note: High intake manifold air temperature, high altitude operation, and/or high engine speeds at high load can cause the exhaust temperature to increase. The exhaust temperature may be allowed to increase to a level that may damage the components of the exhaust system. If the conditions warrant, the ECM may derate the engine power in order to prevent this calculated temperature. The engine derate will avoid potential damage to these engine components.
During an engine derate that is initiated for this calculated temperature, two histograms will begin recording data. The histograms record intake manifold air temperatures and turbocharger compressor inlet air pressures. The histogram data will be recorded by the ECM only while the engine derate is active. Use Cat ET to view the histogram data in order to assist in troubleshooting a low-power complaint.
Check the engine fan system to make sure that the fan is working correctly.
Perform the following procedure:
1. Determine the operating conditions of the engine. Interview the operator, when possible. Determine if an excessive load was placed on the engine during the low-power complaint. Determine if the engine is operating at a high altitude.
If the engine derate is due to normal engine operation, review the histograms for intake manifold air temperatures and turbocharger compressor inlet air pressures. This data will help to determine the cause of the engine derate.
2. Check the aftercooler core for debris.
The intake manifold air temperature can increase if the aftercooler is obstructed. Check the fins of the aftercooler for obstructions. If the fins of the aftercooler are obstructed, clean the fins. Return the engine to service.
3. Check the 5 V supply to the atmospheric pressure sensor and the turbocharger compressor inlet pressure sensors.
If the supply is lost for these sensors, the sensor output will float to a value that is within the operational range of the sensor. The ECM detects this nominal value as a low barometric pressure. The ECM interprets this low barometric pressure as a high altitude condition. The engine is then derated by the ECM for the high altitude condition.
Derate or Altitude
Result: The engine is not operating at a high altitude.
Proceed to the next step.
Result: The engine is operating at a high altitude.
Repair: Make sure that the settings for the engine are correct for the altitude.
If the problem is not resolved, proceed to the next step.
Result: The engine aftercooler is not obstructed.
Proceed to the next step.
Result: The engine aftercooler is obstructed.
Repair: Clear any obstructions or debris in the aftercooler.
If the problem is not resolved, proceed to the next step.
Result: The cooling fan is OK
Proceed to the next step.
Result: The cooling fan is not working correctly
Repair: Repair or replace the cooling fan if necessary.
If the problem is not resolved, proceed to the next step.
Result: The 5 V supply to the atmospheric pressure sensor and the turbocharger compressor inlet pressure sensors are OK..
Proceed to the next step.
Result: The 5 V supply to the atmospheric pressure sensor and the turbocharger compressor inlet pressure sensors are NOT OK.
Repair: If supply voltage is not present at either of the sensor connectors, repair the circuit. Refer to Troubleshooting, "Sensor Supply - Test" for details.
If the problem is not resolved, proceed to the next step.
Table 2
Troubleshooting Test Steps Values Results
2. Check the Low-pressure Fuel System
A. Perform a visual inspection of the fuel system components.
B. Check the fuel pressure during engine cranking. Check the filtered fuel pressure. Refer to Systems Operation/Testing and Adjusting for the correct pressure values.
C. If the fuel pressure is OK, check for air in the fuel system. Refer to Systems Operation/Testing and Adjusting for details.
D. If the fuel pressure is low, replace the fuel filters. If the fuel pressure is still low, refer to Troubleshooting, "Fuel Pressure is Low" for more information that is related to troubleshooting the low-pressure fuel system.
Pressure
Result: The low-pressure fuel system is OK.
Proceed to the next step.
Result: The low-pressure fuel system is NOT OK.
Repair: Determine the fault and repair.
If the problem is not resolved, proceed to the next step.
3. Check the Fuel Injectors for the High-pressure Fuel System
A. If service has been performed on the fuel system recently, use Cat ET to check that the injector trim files are correct.
B. Use Cat ET to ensure that there are not any active diagnostic codes for the injector solenoids. Perform the "Cylinder Cutout Test" in order to check for a misfiring cylinder. Refer to Troubleshooting, "Injector Solenoid - Test" for information that is related to the test.
C. Use Cat ET to perform the "Fuel System Verification Test" in order to check the mechanical condition of the fuel injectors. Refer to Troubleshooting, "Injector Solenoid - Test" for information that is related to the test.
Injector
condition
Result: The injectors check OK.
Proceed to the next step.
Result: A problem with a fuel injector was identified and repaired.
If the problem is not resolved, proceed to the next step.
4. Check for Leakage in the High Pressure Fuel System
This engine is equipped with flow limiters that are installed in the high-pressure fuel rail. If the fuel flow for a particular cylinder becomes excessive, the flow limiter for that cylinder will trip. The following conditions will cause a flow limiter to trip:
- Excessive fueling by a fuel injector
- Excessive bypass by an injector
- Leakage of a connection at the quill tube
A. Test for excess fuel flow through the injectors. Refer to Systems Operation/Testing and Adjusting, "Injector Bypass Fuel Flow - Test" for detailed information.
B. Check for excess fuel leakage in the fuel rail. Refer to Systems Operation/Testing and Adjusting, "Fuel Rail Leakage