CROWN 7J7984 - Caterpillar

Remove fuel return line (1) from the PRV on the high-pressure fuel rail to the low-pressure regulator block.
Cap the port at the regulator block using the 9L-8493 Flared Cap.
Route the PRV fuel line into graduated cylinder (2).Note: Ensure that the PRV fuel line does not have any obstructions or residual fuel.
Use the Cat® Electronic Technician (ET) "Injection Disable Override" to disable the fuel injectors or disconnect the fuel injectors electrical connector on the side of the cylinder head.Note: Leave the injectors disabled during the test.
Turn the keyswitch to ON for 30 seconds to prime the fuel system. After priming has been completed, crank the engine for 20 seconds and record the fuel volume that collects in the graduated cylinder.
If the measured volume of fuel is more than 5 drops, replace the PRV. Repeat the test to verify the repair. Proceed to Test Step 4.
If the measured volume of fuel is fewer than 5 drops, reinstall the PRV fuel line to the low-pressure regulator block. Proceed to Test Step 2.Test Step 2: Measure the Pressure and Flow of the Fuel Rail while Cranking
Illustration 3 g06258456
(3) High-pressure fuel supply line
(5) 323-3950 Discharge Orifice AsNote: Illustration 3 shows discharge orifice assembly (5) attached to injector supply line number 3. The discharge orifice assembly can be installed to any injector supply line as long as the other 5 injectors ports are plugged on the fuel rail.
Remove the fuel lines for the injectors from the fuel rail.
Install the 558-4574 Rail Plug As on the rail for cylinders 1, 2, 4, 5, and 6.
Use the 355-8794 Gage Pin to ensure that the discharge orifice is free of any obstruction.
Illustration 4 g06257833
(5) 323-3950 Discharge Orifice As
Install discharge orifice assembly (5) on injector port 3. Route the discharge orifice assembly hose to the 356-2470 Graduated Cylinder.
Use the Cat® Electronic Technician (ET) "Injection Disable Override" to disable the fuel injectors or disconnect the fuel injectors electrical connector on the side of the cylinder head.Note: Leave the injectors disabled during the test.
Turn the keyswitch to ON for 30 seconds to prime the fuel system. Then crank the engine for 30 seconds and record the fuel volume in the graduated cylinder.
The volume of the fuel is less than 0.25 mm (0.01 inch). Replace the high-pressure fuel pump and proceed to Test Step 4.Note: Ensure that the low-pressure fuel system is providing a minimum of 210 kPa (30.5 psi) during the cranking process.
The volume of the fuel is greater than 0.25 mm (0.01 inch). Proceed to Step 7 to check the fuel rail pressure.
Navigate in Cat ET to the "Status Parameters > Fuel Delivery" screen. Record the "Fuel Rail Pressure" and "Engine Speed" while the engine cranks for 10 seconds. Refer to Table for the minimum values for fuel rail pressure in relation to the engine speed.
Table 2
Engine Speed Range (rpm) 150-174 175-199 200-224 225-250 250-274 275-300
Minimum Cranking Pressure (Mpa/psi) 3640 kPa (528 psi) 5620 kPa (815 psi) 7600 kPa (1102 psi)