The primary function of the nozzles is to distribute the fuel in the combustion chamber, which affects the combustion efficiency and engine performance.
REMOVAL & INSTALLATION
- Disconnect the negative battery cable.
- Disconnect the fuel return line(s) from the fuel injector nozzle(s).
- Disconnect the fuel injection line(s) from the fuel injector nozzle(s).
- Remove the fuel injector nozzle(s) from the engine.
- Inspect and test the fuel injector nozzle(s).
- Install the fuel injector nozzle(s) to the engine.
- Connect the injection line(s) to the fuel injector nozzle(s).
- Connect the fuel return line(s) to the fuel injector nozzle(s).
- Connect the negative battery cable.
See Figure 1
The following procedure requires the use of a reliable pressure tester and Calibrating Oil No. SAE J9670 or equivalent at room temperature, approximately 70°F (20°C).
- Using a reliable pressure tester, connect the test line to a fuel nozzle and tighten the fittings.
- Close the gauge valve and operate the handle several times, then check for proper nozzle spray pattern.
- Open the gauge valve and operate the handle slowly to determine the injector opening pressure. Observe the gauge reading just before the oil is sprayed from the tip; a buzzing noise will occur when the spray is injected. The minimum opening pressure is 1493 psi (10,294 kPa).
- Close the pressure gauge.
- Operate the handle slowly, one stroke every 2 seconds, and observe the spray pattern.
- The spray should be uniform and injected at the correct angle of the nozzle being tested.
- Operate the handle to increase the fuel pressure to 284 psi (1958 kPa).
- Observe the nozzle tip, it should remain dry without an accumulation of fuel at the spray holes; a slight wetting is permitted after 10 seconds, if no droplets are formed.