Fuel Pressure Check 1. Relieve fuel pressure. See FUEL PRESSURE RELIEF. Connect Fuel Pressure Gauge (J-34730-1) to fuel pressure fitting on fuel rail. Turn ignition on with engine off. Fuel pressure should be within specification. See FUEL PRESSURE table. If no fuel pressure is present, go to step 5). 2. Start engine. Fuel pressure should drop 3-10 psi (.2-.7 kg/cm 2 ). Turn ignition off. Pressure should hold. If fuel pressure does not hold, check for leaking injectors or fittings. If injectors or fittings are not leaking, replace fuel pressure regulator. 3. If fuel pressure is less than specified, check for restricted fuel line or fuel filter. Repair as necessary. If no restriction is evident, apply battery voltage to fuel pump test connector using a 10-amp fused jumper wire. For location of fuel pump test connector, see COMPONENT LOCATIONS in the SYSTEM/COMPONENT TESTS article. 4. Gradually pinch off fuel return line between gauge and fuel tank. If fuel pressure increases to within specification, replace fuel pressure regulator. If fuel pressure does not increase with line pinched, check for faulty in-tank fuel pump or partially blocked fuel strainer. 5. Using a 10-amp fused jumper wire, apply battery voltage to fuel pump test connector. For location of fuel pump test connector, see COMPONENT LOCATIONS in the SYSTEM/COMPONENT TESTS article. Observe fuel pressure reading. If fuel pressure is still not present, check wiring between test connector and fuel pump. If wiring is okay, replace fuel pump. 6. If fuel pressure is present with voltage applied to test connector, test fuel pump relay and voltage supply to relay. See the SYSTEM/COMPONENT TESTS article.
Thursday, March 12th, 2009 AT 2:20 PM