Fuel pressure is a bit low, changed the filter? Retest after doing that, here's the specs:
Test pressure this way:
Fuel Pump Testing 1. Visually inspect fuel delivery system for leaks and damaged lines. Ensure battery is fully charged and fuses are okay. Check fuel tank contents and fuel gauge accuracy. 2. Release fuel pressure. See FUEL SYSTEM PRESSURE RELEASE . Install fuel pressure gauge. Turn ignition on to activate pump. Check and record fuel pressure. For fuel pressure specifications, see FUEL PRESSURE SPECIFICATIONS article. Proceed to appropriate step as indicated: Ã If fuel pressure is within specification, go to step 3). Ã If fuel pressure is zero, go to step 5). Ã If fuel pressure is low, go to step 6). Ã If fuel pressure is high, go to FUEL PRESSURE REGULATOR. 3. Check fuel injectors. See FUEL CONTROL . Start or crank engine. Using a mechanic's stethoscope, listen for regularly spaced operating clicks at each injector. If clicks are present, check fuel injectors for flow and leakage. 4. If clicks are not present, check fuel injector resistance. See FUEL CONTROL . Replace injectors not within specification. If injectors are within specification, check for 12 volts at each injector lead. If voltage is present, circuit is okay. Clean or replace injectors as necessary. If voltage is not present at injectors, see CIRCUIT TEST H in TESTS W/CODES - EEC-IV article in the ENGINE PERFORMANCE section for circuit diagnosis. 5. If fuel pressure is zero, ensure battery is fully charged. Ensure connection is okay at pump/sending unit. Turn ignition off. Using a jumper lead, ground FP terminal at self-test connector. See Fig. 6 . Turn ignition on, leaving engine off. Listen for sound of fuel pump. If pump is running, go to next step. If pump is not running, go to step 7). Fig. 6: Fuel Pump Connector Terminal & Circuit ID 6. Check condition of fuel filter. Replace filter if necessary, and repeat step 1). If filter is okay, check fuel pressure regulator. See FUEL PRESSURE REGULATOR. 7. Turn ignition off. Disconnect fuel pump/sending unit connector. Measure resistance between pump ground at connector and chassis ground. If resistance is greater than one ohm, repair open circuit to ground. If resistance is not greater than one ohm, go to next step. 8. Ensure ignition is off and battery is fully charged. Disconnect harness connector from pump/sending unit. Ground FP terminal at self-test connector. Turn ignition on. Measure voltage at pump power terminal of pump/sending unit connector. If voltage is greater than 10.5 volts, replace pump/sending unit assembly. If voltage is not greater than 10.5 volts, go to next step. 9. Check inertia switch. See ENGINE SENSORS & SWITCHES (ECA INPUTS). Check fuel pump relay (if equipped). See RELAYS under MODULES, RELAYS & SOLENOIDS. Check integrated relay control module (if equipped). See MODULES under MODULES, RELAYS & SOLENOIDS. Check engine compartment for leaks and ensure engine produces normal engine vacuum. See FUEL PRESSURE REGULATOR. CAUTION: Inspect fuel system for leaks and damage before testing fuel pump.
Fuel Pressure Regulator 1. Turn ignition off. Ensure vacuum hose is connected to fuel pressure regulator. Start and run engine for 10 seconds. Stop engine, and wait 10 seconds. Start and run engine for 10 seconds. Stop engine. Remove vacuum hose from pressure regulator. If fuel is present in vacuum port, replace fuel pressure regulator. If fuel is not present, go to step 2). 2. Connect fuel pressure gauge to Schrader valve on fuel rail. Ground FP terminal at self-test connector. Turn ignition on. Operate fuel pump for 30 seconds. Stop fuel pump, and check fuel pressure gauge. Ensure fuel pressure is within specification. For fuel pressure specifications, see FUEL PRESSURE SPECIFICATIONS article. Ensure pressure does not drop more than 2 psi (.2 kg/cm 2 ) in 3 minutes. 3. If fuel pressure is within specification, fuel pressure regulator is okay and test is compete. If fuel pressure is not within specification, check fuel filter, and service as necessary. If fuel pressure is still not within specification, install vacuum gauge to intake manifold. Start engine, and observe vacuum and fuel pressure gauge while accelerating and decelerating engine. 4. When engine is accelerating, vacuum reading should decrease and fuel system pressure should increase. When engine is decelerating, vacuum reading should increase and fuel system pressure should decrease. If readings are as indicated, fuel system is okay and test is compete. 5. If gauge readings are not as indicated, turn ignition off. Disconnect and plug fuel pressure regulator hose. Attach vacuum pump to fuel pressure regulator. Start engine. Apply vacuum to pressure regulator while observing fuel pressure gauge. If fuel pressure changes as vacuum changes, repair restriction in vacuum supply hose. If fuel pressure does not change as vacuum changes, replace fuel pressure regulator. 6. Ensure ignition is off. Relieve fuel pressure. Remove fuel pressure regulator. Check "O" ring, gasket and mounting surfaces for cracks, cuts and other damage. See Fig. 7 . Connect vacuum pump to fuel return tube. Apply 20 in. Hg. If maximum vacuum loss exceeds 10 in. Hg in 10 seconds, replace regulator. If maximum vacuum loss does not exceed 10 in. Hg in 10 seconds, recheck entire fuel delivery system for cause of fuel pressure loss CAUTION: Inspect fuel system for leaks and damage before testing fuel pump.
Tuesday, May 4th, 2010 AT 2:14 PM