CAP 4871600 - Caterpillar

Illustration 7 g02527498
Minimum EFLP flow rate in a 12 VDC system
Illustration 8 g02527518
Minimum EFLP flow rate in a 24 VDC system
Table 3
Troubleshooting Test Steps Values Results
7. EFLP Flow Test at the Primary Fuel Filter Inlet
A. Make sure the keyswitch is in the OFF position.
B. Disconnect the fuel inlet connection from the primary fuel filter head.
C. Install a suitable blank on the fuel inlet port on the primary fuel filter head.
D. Place the open end of the fuel inlet line in a suitable calibrated container.
E. With the keyswitch in the ON position, measure the input voltage at the EFLP. Record the result.
F. With the keyswitch in the ON position, measure the flow from the fuel inlet line. Record the result.
G. Check the recorded voltage and fuel flow on the graph in Illustration 7 or 8.
EFLP flow
Result: The fuel flow is below the minimum value for the recorded voltage.
Repair: Replace the EFLP. Refer to Disassembly and Assembly, "Fuel Priming Pump - Remove and Install".
Result: The fuel flow is above the minimum value for the recorded voltage.
Proceed to Test Step 8.
8. Check the Return Fuel Lines
A. Make sure that the TPIR return line is not blocked or kinked.
B. If the TPIR return line is clear, confirm that the Electric Fuel Lift Pump (EFLP) is operating. Make sure that fuel lines between the EFLP and the TPIR are not blocked or kinked.
Return lines
Result: The TPIR return line or the fuel lines between the EFLP and the TPIR are blocked or kinked.
Repair: Clear or replace the blocked line.
Result: The TPIR return line and the fuel lines between the EFLP and the TPIR are clear.
Repair: Replace the EFLP.
If the fault is still present, proceed to Test Step 9.
9. High-Pressure Fuel System
A. Use the electronic service tool to check the absolute fuel rail pressure while the engine is cranking at a minimum speed of 150 rpm.
High-pressure fuel system
Result: The absolute fuel rail pressure is less than 25 MPa (3625 psi).
Repair: Check for fuel leaks in the high-pressure fuel system. Rectify any fuel leaks and then recheck the pressure in the fuel rail.
Use the electronic service tool to perform a solenoid test on the fuel injection pump.