Part 2 of 3

Chart A-7 - Part 2 Of 3:

Fuel Line Hookups:

TEST DESCRIPTION
Numbers below refer to circled numbers on the diagnostic chart.

5. Fuel pressure that drops off during acceleration, cruise or hard cornering may cause a lean condition and result in a loss of power, surging or misfire. This condition can be diagnosed using a Tech 1 (or equivalent) scan tool. If the fuel system is very lean, the O2S voltage will stop toggling and will drop below 500 mV. Also, the injector pulse width will increase.


6. Fuel pressure below 284 kPa (41 psi) may cause a lean condition and may set DTC 44 or DTC 32. Driveability conditions can include hard starting cold, hesitation, poor driveability, lack of power, surging or misfire.

7. Restricting the fuel return line causes fuel pressure to build above regulated pressure. With battery voltage applied to the pump "test" terminal, pressure should rise above 325 kPa (47 psi) as the valve in the return line is partially closed.

CAUTION: Do Not allow pressure to exceed 414 kPa (60 psi) as damage to the regulator may result.


8. Fuel pressure above 325 kPa (47 psi) may cause a rich condition and may set a DTC 45. Driveability conditions can include hard starting (followed by black smoke) and a strong sulphur smell in the exhaust.

9. This test determines if the high fuel pressure is due to a restricted fuel return line or a faulty fuel pressure regulator.