Testing Fuel Injectors
WARNING:
Avoid all contact with fuel spray. The high pressure pump supplies high-pressure fuel to each individual injector through high-pressure lines. Fuel under this amount of pressure can penetrate skin and cause personal injury. Wear safety goggles and adequate protective clothing when servicing fuel system.
NOTE:
The fuel pump pressure must be 1.5 bar (22 psi.), and the engine must be at operating temperature 80°C (176°F).
- Run the engine until operating temperature is obtained.
- Turn OFF the ignition.
- Disconnect the fuel injector return hose at the return hose fitting directly below the fuel pressure solenoid
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1 - FUEL INJECTOR 2 - FUEL RAIL SUPPLY 3 - FUEL RETURN LINE TO FUEL FILTER/FUEL HEATER 4 - FUEL INJECTOR RETURN HOSE 5 - FUEL RAIL 6 - HIGH PRESSURE FUEL INJECTOR LINE - Block off fuel return fitting at the fuel rail.
- Place the fuel return hose into a suitable container.
- Start the engine and measure the amount of return fuel into the container for one minute at idle.NOTE: If the quantity of fuel is above 100 ml. it means one or more of the fuel injectors has a problem.
- If the measured quantity is above 100ml, reconnect the return hose at the fitting, disconnect each injector return hose singularly, at the injector and measure the amount of return fuel into the container.NOTE: Make sure to block off the fuel return hose at each individual injector before making the measurement.
- Replace the fuel injector that has a return rate above 25 ml. for one minute. See Fuel System/Fuel Injection/INJECTOR(S), Fuel - Removal .