68879 Mercury COVER

Table 1
Required Tools    
Tool     Part Number     Part Description     Qty    
A     5P-4150     Nozzle Testing Group     1    
B     5P-4718     Adapter     1    
C     6V-2170     Tube Assembly     1    
D     8T-5313     Filter     1    
E     1U-8857     Extension     1    
F     8S-2270     Fuel Collector     1    
G     6V-6068     SAE J-967 Calibration Fluid     1    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 g01228000
Fuel injection nozzles and lines (1) Nut for the fuel supply line
Run the engine at low idle.
Loosen the nut for the fuel supply line (1) at the fuel injection nozzle on cylinder number 1. Do not loosen the nut more than half of a turn. Listen for the low idle to decrease or become rough. Tighten the nut for the fuel supply line on cylinder number 1. Perform this test on each cylinder.
The fuel injection nozzle is faulty when the nut for the fuel supply line is loosened and the following events occur:
The engine rpm does not decrease.
The engine does not idle roughly.
Remove the faulty 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 the 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, use an ultrasonic cleaner to 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
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 g01242713
5P-4150 Nozzle Testing Group (1) Fuel injection nozzle (B) 5P-4718 Adapter (C) 6V-2170 Tube assembly (D) 8T-5313 Filter (Not shown) (E) 1U-8857 Extension (F) 8S-2270 Fuel collector
Do not use dirty test fluids when you test fuel injection nozzles. Also, do not test fuel injection nozzles unless you have the correct service tools.The use of dirty test fluids and the use of incorrect service tools will result in damage to fuel injection nozzles.
Connect fuel injection nozzle (1) to the tooling that is shown in Illustration 2.Position the fuel injection nozzle so that the fuel spray is directed into Tooling (E) and Tooling (F) .Use Tooling (G) that is clean when the fuel injection nozzles are tested. Tooling (G) is equivalent to SAE J-967 (ISO 4113) oil.
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.
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 the valve needle is lifted from the valve seat.
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.Test the Spray Pattern
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.