BOOM CHECK VALVES AND LINES GROUP 2V1122 - Caterpillar

Low Fuel Rail Pressure
A. Make sure that the level of fuel in the fuel tank is sufficient. If necessary, fill the fuel tank.
B. Inspect the high-pressure fuel system for leaks.
C. Use the electronic service tool to perform the "High Pressure Fuel Pump Calibration".
D. Check that the Electric Fuel Lift Pump (EFLP) is operating.
E. Check for air in the low-pressure fuel system. Refer to Systems Operation, Testing, and Adjusting, "Air in Fuel - Test".
F. Use the electronic service tool in order to perform the "Fuel Rail Pressure Relief Valve Test".
Note: This test will identify excessive leakage through the PLV in the fuel rail.
   
Low fuel rail pressure
   
Result: The high-pressure fuel system has a leak.
Rectify any fuel leaks.
Result: The Electric Fuel Lift Pump (EFLP) is not operating correctly.
Refer to Troubleshooting, "Fuel Pump Relay Circuit - Test".
Result: There is air in the low-pressure fuel system.
Identify the cause of the air in the system. Remove the air from the low-pressure fuel system. Refer to Systems Operation, Testing, and Adjusting, "Air in Fuel - Test".
Result: The Fuel Rail Pressure Relief Valve Test fails.
If excessive leakage is identified, replace the fuel rail. Refer to Disassembly and Assembly, "Fuel Manifold (Rail) - Remove and Install".
If the fault is still present, turn the isolator switch to the OFF position and disconnect the electrical connector from the EFLP.
With the isolator switch in the ON position, measure the voltage at the harness connector for the EFLP. The voltage must be between 10 VDC and 14 VDC for a 12 VDC system. The voltage must be between 20 VDC and 28 VDC for a 24 VDC system. If the voltage is below 10 VDC for a 12 VDC system, investigate the cause. If the voltage is below 20 VDC for a 24 VDC system, investigate the cause. Refer to Troubleshooting, "Fuel Pump Relay Circuit - Test"
Turn the isolator switch to the OFF position and then reconnect the electrical connector to the EFLP.
If a repair has been performed to rectify a low supply voltage to the EFLP, check for the original fault. If the fault is still present, proceed to Test Step 10.
Result: The fuel system is OK.
Proceed to Test Step 13.
   
Illustration 6 g03582241
Transfer Pump Inlet Regulator (TPIR) components (1) Fuel return to the secondary fuel filter (2) Transfer Pump Inlet Regulator (TPIR) (3) TPIR return port
Illustration 7 g02485896
Minimum TPIR flow rate with a 12 VDC system
Illustration 8 g02485897
Minimum TPIR flow rate with a 24 VDC system
Table 5
Troubleshooting Test Steps    Values    Results    
10. Transfer Pump Inlet Regulator (TPIR) Flow Test
Refer to Illustration 6.
A. Disconnect the TPIR return line from the drain port on the TPIR. Install a suitable blanking cap on the open port in the TPIR return line.
B. Connect a temporary drain line to the drain port on the TPIR.
C. Place the end of the temporary drain line into a suitable calibrated container.
D. With the isolator switch in the ON position but the engine not running, use a suitable multimeter to measure the input voltage to the