Part 2 of 3

Chart A-7 (Part 2 Of 3):

Fuel Flow Diagram:

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

1. Pressure below 284 kPa (41 psi) may cause a lean condition and may set Code 44. It could also cause hard starting cold and poor driveability. Low enough pressure will cause the engine not to run at all. Restricted flow may allow the engine to run at idle, or low speeds, but may cause a surge and stall when more fuel is required, as when accelerating or driving at high speeds.

2. Restricting the the fuel return line allows 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 return hose is gradually pinched.

CAUTION: DO NOT allow pressure to exceed 414 kPa (60 psi), as damage to the regulator may result.

3. This test determines if the high fuel pressure is due to a restricted fuel return line or a faulty pressure regulator. High fuel pressure may cause a rich condition and may set a Code 45.