Part 2 of 4

TEST DESCRIPTION

Fuel Delivery Diagram (Adapters Shown Installed For Testing):

Chart A-7, Fuel System Diagnosis (2 OF 4):

Numbers below refer to circled numbers on the diagnostic chart.

1. Fuel pressure below specified can cause an excessive lean condition resulting in the following symptoms, and/or set a Code 44:

a. Hard starting
b. Stalling
c. Poor driveability
d. Low power, surging (especially mid-to-high speed, may idle OK)
e. Engine backfire under load - shuddering

2. Restricting the fuel return line should cause fuel pressure to rise above regulated pressure. If it does, the problem is a faulty pressure regulator. If pressure does not increase to at lease 284kPa (41 psi), then fuel is not being supplied from the pressure line (plugged fuel filter, bad fuel pump, plugged strainer in tank, kinked fuel line or tube, leak, etc.)

CAUTION: Do NOT allow pressure to exceed 414 kPa (60 psi) while performing this test, damage to the pressure regulator will result
.
3. This test will determine if the high fuel pressure is due to a restricted fuel return line or defecttive pressure regulator.

NOTE: High fuel pressure may cause an excessive rich condition and set a Cod 45.