Perkins NJ Series Troubleshooting Manual page 55

SENR9982-01
2. Ensure that the fuel supply valve (if equipped) is
in the full OPEN position.
3. If the temperature is below 0 °C (32 °F), check
for solidified fuel (wax).
4. Check the primary filter/water separator for water
in the fuel.
5. Check for fuel supply lines that are restricted.
6. Check that the low pressure fuel lines are tight
and secured properly.
7. Check the fuel filters.
8. Check the diesel fuel for contamination. Refer to
Testing and Adjusting, "Fuel Quality - Test".
9. Check for air in the fuel system. Refer to Testing
and Adjusting, "Air in Fuel - Test".
10. Ensure that the fuel system has been primed.
Refer to Testing and Adjusting, "Fuel System -
Prime".
11. If the repair does not eliminate the fault refer to
"Low Compression (Cylinder Pressure)".
Low Compression (Cylinder Pressure)
1. Perform a compression test. Refer to Testing and
Adjusting, "Compression - Test ".
2. If low compression is noted on any cylinders,
investigate the cause and rectify the cause.
Possible causes of low compression are shown
in the following list:
• Loose glow plugs
• Faulty piston
•
Faulty piston rings
• Worn cylinder bores
• Worn valves
•
Faulty cylinder head gasket
• Damaged cylinder head
3. Perform all necessary repairs.
4. Ensure that the repairs have eliminated the faults.
5. If the repair does not eliminate the fault refer to
"Electronic Control System".
Electronic Control System
1. Use the electronic service tool to check that fuel
pressure is present in the fuel rail when the engine
is cranking.
2. If the pressure demand for the fuel rail is greater
than 5 MPa (725 psi), refer to "High Pressure Fuel
System".
3. If the pressure demand for the fuel rail is less
than 5 MPa (725 psi), check the operation of the
primary speed/timing sensor and the secondary
speed/timing sensor. Refer to the Troubleshooting
Guide, "Engine Speed/Timing Sensor Circuit -
Test". If necessary, replace any faulty sensor.
4. Make sure that any repairs have eliminated the
fault.
High Pressure Fuel System
Use the electronic service tool to monitor a stable
fuel rail pressure during engine cranking.
If the fuel rail pressure is less than 5 MPa (725 psi),
perform the following procedure.
1. Check the current to the solenoid valve in the
fuel injection pump. If no current is detected,
investigate the cause of the fault.
2. Use the electronic service tool to perform
the"Injector Solenoid Test". If an injector fails the
test, determine whether the fault is caused by the
wiring, the ECM or the injector.
3. Install a test ECM in order to determine whether
the ECM is the cause of the fault. Refer to the
Troubleshooting Guide, "Replacing the ECM".
4. Test the function of the fuel rail pressure sensor.
Refer to the Troubleshooting Guide, "Engine
Pressure Sensor Open or Short Circuit - Test". If
the pressure sensor is faulty, replace the pressure
sensor.
5. If the fault is still apparent, replace the fuel injection
pump. [Refer to Disassembly and Assembly, "Fuel
Injection Pump - Remove" and Disassembly and
Assembly, "Fuel Injection Pump - Install".
If the fuel rail pressure is greater than 5 MPa
(725 psi), perform the following procedure.
1. Check for leakage from the pressure relief valve
in the fuel rail. If there is any leakage, replace the
fuel rail.
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Troubleshooting Section