K Yukon/Denali 4WD V8-5.7L VIN R (2000)
associated with rich conditions can include hard starting followed by black smoke and a strong sulfur smell in the exhaust.
12. This test determines if the high fuel pressure is due to a restricted fuel return pipe or if the high fuel pressure is due to a faulty fuel pressure
regulator.
14. A lean condition may result from the fuel pressure being below 414 kPa (60 psi). A lean condition may cause a DTC to set. Driveability
conditions associated with lean conditions can include hard starting, when the engine is cold, hesitation, poor driveability, lack of power, surging,
and misfiring.
15. Restricting the fuel return pipe with the J 42873-2 fuel pipe shut-off adapter causes the fuel pressure to rise above the regulated fuel pressure.
Using a scan tool to pressurize the fuel system, the fuel pressure should rise above 455 kPa (66 psi) as the valve on the fuel pipe shut-off adapter
connected to the fuel return pipe becomes partially closed.
22. If the injectors are not grounded, check the spark plug associated with a particular fuel injector for fouling or saturation in order to determine if
that particular fuel injector is leaking. If checking the spark plug associated with a particular fuel injector for fouling or saturation does not
determine that a particular fuel injector is leaking, use the following procedure:
1. Remove the fuel meter body assembly.
2. Reinstall the engine compartment fuel teed and return pipes to the fuel meter body and the chassis fuel pipes.
3. Lift the fuel meter body assembly just enough to leave the fuel injector poppet nozzles in the ports.
4. Pressurize the fuel system by using the scan tool fuel pump enable.
5. Visually and physically inspect the fuel injector poppet nozzles for leaks.
