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Chart A-7 (2 of 2):

Fuel System Schematic.:

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

1. Amount of fuel to injectors OK, but pressure is low, less than 62.0 kPa (9.0 psi). System will be lean running and may set a Code 44. Also, hard starting cold and poor overall performance may result. Restricted flow causing pressure drop. Normally, a vehicle with a fuel pressure of less than 62.0 kPa (9.0 psi) at idle will not be driveable. However, if the pressure drop occurs only while driving, the engine will normally surge then stop as pressure begins to drop rapidly.
2. Restricting the fuel supply line at the fuel pressure gauge causes the fuel pump to develop its maximum pressure. With the fuel pump running, pressure should rise above 90.0 kPa (13.0 psi) as the gauge hose is restricted.
NOTE: DO NOT restrict the fuel return line. This may damage the fuel pressure regulator.
3. This test determines if the high fuel pressure problem is due to a restricted fuel return line or a throttle body pressure regulator problem.