C9.3B Engines Caterpillar

Required Parts

Illustration 1	g02039499
323-3949 Test Kit (1) 356-2468 Foam Lid (2) 356-2470 Graduated Cylinder (3) 356-2466 Plastic Case (4) 323-3950 Discharge Orifice As (5) 323-8301 Pump Drain Hose (6) 355-8794 Gage Pin (7) 356-2469 Foam Block (8) 355-8626 Nut (9) 558-4574 Rail Plug As(1)

Test Procedure

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Contact with high pressure fuel may cause personal injury or death. Wait 60 seconds after the engine has stopped to allow fuel pressure to purge before any service or repair is performed on the engine fuel lines.

Note: Use the gage pin (6) or an aerosol cleaner to ensure that the orifice is clean before performing this procedure.

Test Step 1: Measure the Fuel Leak From the Pressure Relief Valve (PRV)

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Illustration 2	g06258452
(1) Pressure Relief Valve (PRV) fuel line

1. Remove fuel return line (1) from the PRV on the high-pressure fuel rail to the low-pressure regulator block.

   1. Cap the port at the regulator block using the 9L-8493 Flared Cap.

   2. Route the PRV fuel line into graduated cylinder (2).

      Note: Ensure that the PRV fuel line does not have any obstructions or residual fuel.

2. 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.

3. 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.

   1. 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.

   2. 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

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Illustration 3	g06258456
(3) High-pressure fuel supply line (5) 323-3950 Discharge Orifice As

Note: 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.

1. Remove the fuel lines for the injectors from the fuel rail.

2. Install the 558-4574 Rail Plug As on the rail for cylinders 1, 2, 4, 5, and 6.

3. Use the 355-8794 Gage Pin to ensure that the discharge orifice is free of any obstruction.
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   Illustration 4	g06257833
   (5) 323-3950 Discharge Orifice As

4. Install discharge orifice assembly (5) on injector port 3. Route the discharge orifice assembly hose to the 356-2470 Graduated Cylinder.

5. 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.

6. 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.

   1. 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.

   2. The volume of the fuel is greater than 0.25 mm (0.01 inch). Proceed to Step 7 to check the fuel rail pressure.

7. 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.
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   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)	10260 kPa (1488 psi)	12910 kPa (1872 psi)	16000 kPa (2320 psi)

   1. The fuel rail pressure remains less than the minimum fuel rail pressure rated against the engine speed listed in the table. Replace the high-pressure fuel pump. Proceed to Test Step 4.

   2. The fuel rail pressure is greater than or equal to the minimum fuel rail pressure rated against the engine speed listed in the table. Proceed to Test Step 3.

8. Remove the discharge orifice assembly from the fuel rail.

Test Step 3: Measure the Leakage for Individual Injectors

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Illustration 5	g06257834
(6) Injector 3 fuel supply port (7) Injector 4 fuel supply line

1. Connect the fuel supply line for one of the injectors (6) or (7) to the high-pressure fuel rail. Plug the other 5 injector ports using the 558-4574 Rail Plug As.

   Note: Leave the injectors disabled during the test.

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   Illustration 6	g06257836
   (2) 356-2470 Graduated Cylinder (4) 323-8301 Pump Drain Hose (8) Fuel return line

2. Remove fuel return line (8) from the cylinder head and the low-pressure regulator block. Install and tighten the 8S-4950 Cap on the regulator block after removal of the fuel return line.

3. Install pump drain hose (4) onto the cylinder head. Route the pump drain hose into graduated cylinder (2).

   Note: Push the pump drain hose onto the outlet port. The hose does not contain threads for installation.

4. Crank the engine for 30 seconds then stop. Then crank the engine for an extra 30 seconds and stop. Measure the fuel collected from the total 60 second duration.

   Note: The fuel measured is the leakage of the fuel injectors.

   1. The fuel leakage from the injector should be below 30 mL (1.02 oz) from the 60 second cranking duration.

   2. Perform Steps 1 through 3 on each individual injector and record the leakage results.

   3. If an injector leaks more than 30 mL (1.02 oz), then replace the injector. Proceed to Test Step 4.

Test Step 4: Verification of the Repair

1. Replace and torque all the high-pressure fuel rail lines that were loosened during the procedure.

   Note: The high-pressure fuel rail lines are one time use lines.

2. Reconnect and torque the fuel cooling flow supply and return lines for the cylinder head.

3. After inspection/repair of the fuel system, perform the "Fuel Rail Pressure Test" using Cat ET to confirm that the system is operating properly.