3054 and 3056 Marine Generator Set Engines Caterpillar

Test the Fuel Injection Nozzles

Perform the following procedures in order to determine if a fuel injection nozzle does not work correctly.

Bench test the fuel injection nozzles at a temperature of 18° to 20 °C (64° to 70 °F).

Illustration 1	g00804139
Fuel injection nozzles and lines (1) Nut for the fuel supply line

1. Run the engine at low idle.

2. Loosen the nut for the fuel supply line (1) at the fuel injection nozzle on cylinder number 1. Listen for the low idle to decrease or become rough. Tighten the nut for the fuel supply line (1) on cylinder number 1. Perform this test on each cylinder.

3. The fuel injection nozzle is faulty when the nut for the fuel supply line (1) is loosened and the following events occur:
   • The engine rpm does not decrease.

   • The engine does not idle roughly.

   Remove the fuel injection nozzle for additional testing.

   Note: If leakage occurs at the nut for the fuel supply line, make sure that fuel supply line and the nut are correctly aligned with the inlet connection of fuel injection nozzle. Do not tighten the nut for the fuel supply line on the high pressure fuel line more than the recommended torque. If the nut is tightened more, the fuel line may become restricted or the threads of the fuel injection nozzle and the nut may be damaged.

Cleaning of the Fuel Injection Nozzles

Before a fuel injection nozzle is tested, remove any loose carbon from the tip of the fuel injection nozzle. Do not use abrasive material or a wire brush in order to clean the nozzle.

The fuel injection nozzle is not a serviceable part. Disassembling or adjusting the nozzle will violate the standards for emissions.

Note: Extra care should be used in handling the fuel injection nozzle in order to prevent damage to the nozzle tip. A scratch or a burr could cause needle leakage or spray distortion. Dirt in the orifices of the nozzle tip can damage engine components. Dirt can also distort the spray pattern of the nozzle.

Pressure Test

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Ensure that you wear eye protection at all times during testing. When fuel injection nozzles are tested, test fluids travel through the orifices of the nozzle tip with high pressure. Under this amount of pressure, the test fluid can pierce the skin and cause serious injury to the operator. Always keep the tip of the fuel injection nozzle pointed away from the operator and into the fuel collector and extension.

Illustration 2	g00804566
5P-4150 Nozzle Testing Group (1) 5P-7448 Adapter (2) Fuel injection nozzle (3) 6V-2170 Tube assembly (4) 1U-8857 Extension (5) 8S-2270 Fuel collector (6) 8T-5313 Filter

1. Connect fuel injection nozzle (2) to the tooling that is shown in Illustration 2.

   Position the fuel injection nozzle so that the fuel spray is directed into the 1U-8857 Extension (4) and the 8S-2270 Fuel Collector (5) .

   Use clean 6V-6068 Calibration Fluid when the fuel injection nozzles are tested. The calibration fluid is equivalent to SAE J-967 (ISO 4113) oil.

2. Close the gauge protector valve. Close the shutoff valve. Open the pump isolator valve. In order to flush the fuel injection nozzle, operate the nozzle tester for 10 to 15 strokes at a rate of approximately 60 strokes per minute.

3. Open the gauge protector valve. Slowly increase the pressure until the valve in the fuel injection nozzle opens. Note the highest pressure indication on the dial indicator before the pointer moves to 0 kPa (0 psi). This highest pressure indication is the opening pressure of the fuel injection nozzle. The opening pressure is defined when valve needle is lifted from the valve seat.

4. Refer to the table in Specifications, "Fuel Injection Nozzles" for the correct pressure settings.

   If the opening pressure is not within the range of the setting that is given in the table, the fuel injection nozzle must be replaced.

Back Leakage Test

1. Connect fuel injection nozzle (2) to the tooling that is shown in Illustration 2.

   Position the fuel injection nozzle so that the fuel spray is directed into the 1U-8857 Extension (4) and the 8S-2270 Fuel Collector (5) .

2. Pump the pressure to about 1030 kPa (150 psi) below the opening pressure of the fuel injection nozzle.

   Refer to Specifications, "Fuel Injection Nozzles" for the correct setting of the opening pressure.

   Release the handle. When the pressure begins to decrease, note the time that is required for the pressure to decrease to approximately 0 kPa (0 psi). If the fuel injection nozzle is not faulty, the time will not be less than 5 seconds or more than 45 seconds.

3. When the test in Step 2 is done, look for any leakage from the pressure faces of the holder and the retaining nut of the fuel injection nozzle. If leaks are visible, make sure that the components are tightened to the correct torque. Do not overtighten the components in order to stop the leakage. Instead, a pressure test on the fuel injection nozzle must be conducted. This test may force any foreign particles out of the nozzle. Replace the fuel injection nozzle if there is excessive fuel leakage.

4. If the pressure decreases to 0 kPa (0 psi) in less than 5 seconds, too much fuel is leaking around the valve needle. The valve needle or the fuel injection nozzle must be replaced in order to correct the problem.

Fuel Injection Nozzle and Seat Test

1. Connect fuel injection nozzle (2) to the tooling that is shown in Illustration 2.

   Position the fuel injection nozzle so that the fuel spray is directed into the 1U-8857 Extension (4) and the 8S-2270 Fuel Collector (5) .

2. Pump the pressure of the nozzle tester to approximately 1030 kPa (150 psi) below the opening pressure of the fuel injection nozzle. A drop of fuel should not form on the tip of the fuel injection nozzle for at least ten seconds. A light dampness is acceptable. If the results of the tests are not acceptable, clean the fuel injection nozzle. After you clean the fuel injection nozzle and fuel leakage occurs, the nozzle must be replaced.

Test the Spray Pattern

The pressure adjustment must be correct before the spray pattern is tested.

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Ensure that you wear eye protection at all times during testing. When fuel injection nozzles are tested, test fluids travel through the orifices of the nozzle tip with high pressure. Under this amount of pressure, the test fluid can pierce the skin and cause serious injury to the operator. Always keep the tip of the fuel injection nozzle pointed away from the operator and into the fuel collector and extension.

Illustration 3	g00322083
Correct spray pattern for a fuel injection nozzle

1. Connect fuel injection nozzle (2) to the tooling that is shown in Illustration 2.

   Position the fuel injection nozzle so that the fuel spray is directed into the 1U-8857 Extension (4) and the 8S-2270 Fuel Collector (5) .

2. Close the gauge protector valve and the shutoff valve. Open the pump isolator valve.

3. Quickly pump the nozzle tester and look at the spray pattern when the fluid begins to flow through the orifices of the fuel injection nozzle.

   The spray, which flows from all of the orifices, must have the same pattern. The fuel injection nozzle is faulty if there is a difference in the vertical patterns or a difference in the horizontal patterns. Refer to the correct spray pattern in Illustration 3.

   Note: Be sure that the gauge protector valve is closed before the fuel injection nozzle is removed from the nozzle tester. Closing the valve will prevent damage to the pressure gauge.

Installation of the Fuel Injection Nozzles

Illustration 4	g00912369
(1) Clamp (2) Spacer (3) Dust seal (4) Body (5) Seat washer

When a fuel injection nozzle is removed from the cylinder head, replace seat washer (5) and dust seal (3). If the seat washer remains in the recess of the cylinder head, the protrusion of the fuel injection nozzle into the engine cylinder will be incorrect. Also, if the seat washer is damaged, the protrusion of the fuel injection nozzle into the engine cylinder will be incorrect.

Note: Dust seal (3) is positioned under spacer (2) and clamp (1). The dust seal is positioned on the face of the cylinder head.