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B-4: Fuel Pressure Inspection: Aerio

  1. Check fuel pressure as ignition switch is cycled on and off. See appropriate fuel pressure test under FUEL PRESSURE  . If fuel pressure is 38.4-44.0 psi (2.7-3.1 kg/cm2 ), go to next step. If fuel pressure is not as specified, go to step  5 .
  2. After testing fuel pressure and fuel pump stops, fuel system should hold 29 psi (2.0 kg/cm2 ) of pressure or greater for one minute. If fuel pressure holds as specified, go to next step. If fuel pressure does not holds as specified, go to step  4 .
  3. Start engine and allow it to reach normal operating temperature. Check fuel pressure with engine running at idle speed. Fuel pressure should be 31.3-36.9 psi (2.2-2.6 kg/cm2 ). If fuel pressure is as specified, system is operating properly. If fuel pressure is not as specified, check for clogged vacuum hose passage to fuel pressure regulator or faulty fuel pressure regulator. Repair or replace as necessary. After repair, retest system for normal operation.
  4. Check for fuel leaks at fuel feed hose, pipe or connections. If no leaks are present, go to step  10 . If leaks are present, repair or replace as necessary. After repair, retest system for normal operation.
  5. If fuel pressure is greater than 38.4-44.0 psi (2.7-3.1 kg/cm2 ), go to next step. If fuel pressure is lower than 38.4-44.0 psi (2.7-3.1 kg/cm2 ), go to step  7 .
  6. Disconnect fuel return hose from fuel pressure regulator. Connect a separate hose to pressure regulator and insert hose end into a container. Turn ignition switch to ON position. If fuel pressure is 38.4-44.0 psi (2.7-3.1 kg/cm2 ), repair or replace restriction in fuel return hose. If fuel pressure is not as specified, replace fuel pressure regulator. See FUEL PRESSURE REGULATOR under FUEL SYSTEM in REMOVAL & INSTALLATION article. After repair, retest system for normal operation.
  7. If no fuel pressure is present, go to next step. If fuel pressure is present and is less than 38.4-44.0 psi (2.7-3.1 kg/cm2 ), go to step  9 .
  8. Pinch fuel return hose. Turn ignition switch to ON position. If fuel pressure does not increases, go to B-3: FUEL PUMP CIRCUIT INSPECTION  . If fuel pressure increases, replace fuel pressure regulator. See FUEL PRESSURE REGULATOR under FUEL SYSTEM in REMOVAL & INSTALLATION article. After repair, retest system for normal operation.
  9. Pinch fuel return hose. Turn ignition switch to ON position. If fuel pressure is 63.9 psi (4.5 kg/cm2 ) or greater, replace fuel pressure regulator. See FUEL PRESSURE REGULATOR under FUEL SYSTEM in REMOVAL & INSTALLATION article. If fuel pressure is lower than 63.9 psi (4.5 kg/cm2 ), check for clogged fuel filter, restricted fuel feed hose, faulty fuel pump or fuel leakage at hose connection in fuel tank. Repair or replace as necessary. After repair, retest system for normal operation.
  10. Disconnect fuel return hose from pressure regulator. Connect a separate hose to pressure regulator and insert hose end into a container. Recheck fuel pressure. If fuel is discharged into container, replace fuel pressure regulator. See FUEL PRESSURE REGULATOR under FUEL SYSTEM in REMOVAL & INSTALLATION article. If fuel does not discharge into container, check for leaking injector or fuel rail, faulty fuel pump check valve or leaking fuel pressure regulator diaphragm. Repair or replace as necessary. After repair, retest system for normal operation.
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