Grand Caravan L4-153 2.5L SOHC VIN K TBI (1988)
Fuel Pressure: Testing and Inspection
Fuel Pressure Test
NOTE: Fuel system pressure must be released each time a fuel hose is to be disconnected. Perform Fuel Pressure Release procedure.
FUEL PRESSURE TEST
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Disconnect 5/16 fuel supply hose from the engine fuel line assembly. Use care when removing the fuel hose to prevent damage to the hose or the
fuel line. Replace hose if damaged. Connect fuel system pressure tester between fuel supply hose and engine fuel line assembly.
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Using diagnostic tester, with the key in the "RUN" position, depress the ATM button, this will activate the fuel pump and pressurize the system.
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If the gauge reads 93-107 Kpa (13.5-15.5 psi), pressure is correct and further testing is not required. Reinstall fuel hose using a new original
equipment type clamp, and torque to 1 Nm (10 in lb).
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If pressure is not correct, record the pressure and continue with test procedure.
CAUTION: When using the ASD Fuel System Test, the Auto Shutdown (ASD) relay will remain energized for 7 minutes or until the test is
stopped, or until the ignition switch is turned to the "OFF" position.
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If fuel pressure is below specifications, install tester in the fuel supply line, between the fuel tank and fuel filter at the rear of vehicle.
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Repeat test.
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If pressure is 5 psi higher than previously recorded pressure, replace fuel filter.
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If no change is observed, gently squeeze return hose.
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If pressure increases, replace pressure regulator.
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If no change is observed, problem is either a plugged pump filter sock or defective fuel pump.
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If pressure is above specifications, remove the fuel return line hose from the chassis line at the fuel tank and connect a 3 foot piece of fuel hose to
the return line. Put the other end into an approved gasoline container (minimum 2 gallon size) so that all return fuel will flow into container.
Repeat test. If pressure is now correct, check in-tank return hose for kinking. Replace fuel pump assembly if in-tank reservoir check valve or
aspirator jet is obstructed.
NOTE: This test should be performed when fuel tank is 1/2 full or greater.
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If pressure is still above specifications, remove fuel return hose from throttle body. Connect a substitute hose to the throttle body return nipple and
place other end of hose in a clean container. Repeat test.
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If pressure now correct, check for restricted fuel return line.
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If no change is observed, replace fuel pressure regulator.
