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Hombre (2.2L)

NOTE: For diagnosing fuel system, fuel pressure gauge SST J29658-D or equivalent, TECH II scan tool or equivalent and SST J 37287 fuel line shut-off adaptor are required.
  1. Perform On-Board Diagnostic II (OBD-II) System Check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in SELF-DIAGNOSTICS - INTRODUCTION article. After performing OBD-II system check, go to next step.
  2. Turn ignition off. Turn A/C off. Relieve fuel system pressure. See FUEL SYSTEM PRESSURE RELEASE . Turn ignition on. Bleed all air out of fuel pressure gauge. Turn ignition off for 10 seconds, then back on. Observe fuel pressure reading on gauge while fuel pump is running (first two seconds). Cycle ignition switch on and off several times to achieve highest possible fuel pressure. If fuel pressure is within specifications, go to next step. See FUEL PUMP PERFORMANCE  table. If fuel pressure is not within specifications, go to step  12.
    FUEL PUMP PERFORMANCE

    Application Specification
    Amigo, Rodeo & Trooper
    Operating Pressure 42-55 psi (3.0-3.9 kg/cm2 )
    Pressure Drop 3-15 psi (0.2-1.1 kg/cm2 )
    Hombre
    Operating Pressure 41-47 psi (2.9-3.3 kg/cm2 )
    Pressure Drop 3-10 psi (0.2-0.7 kg/cm2 )
  3. Note fuel pressure after fuel pump stops running. It should stabilize and remain constant. If fuel pressure drops more than 5 psi (.35 kg/cm2 ) in ten minutes, go to step  10. If fuel pressure does not drop more than 5 psi (.35 kg/cm2 ) in ten minutes, go to next step.
  4. Bleed off fuel pressure down to 41 psi (2.9 kg/cm2 ). Observe fuel pressure. If fuel pressure drops more than 10 psi (.7 kg/cm2 ) in ten minutes, go to step  21. If fuel pressure does not drop as much as specified, go to next step.
  5. If fuel pressure is suspected of dropping off during acceleration, cruise or hard cornering, go to next step. Otherwise, go to step  8.
  6. Check fuel filter and fuel lines for restrictions. Repair or replace as necessary. If no problem was found, go to step  24.
  7. Drain and remove fuel tank. Remove and inspect fuel pump strainer for restriction. Check fuel pump flex pipe for leaks. Check to be sure that correct fuel pump is installed.Repair as necessary. If any problems were found, go to step  24. If no problems were found, go to step  20.
  8. Start engine and allow it to idle at normal operating temperature. If fuel pressure is between 31-44 psi (2.2-3.1 kg/cm2 ), go to SYMPTOMS in TROUBLE SHOOTING - NO CODES article. If fuel pressure is not as specified, go to next step.
  9. Disconnect fuel pressure regulator vacuum hose and apply 12-14 in. Hg. (41-47 kPa) to regulator. If fuel pressure remains constant and between 31-44 psi (2.2-3.1 kg/cm2 ), go to step  19. If fuel pressure is not as specified, go to step  20.
  10. Turn ignition off and relieve fuel pressure. See FUEL SYSTEM PRESSURE RELEASE . Connect SST J 37287 fuel pipe shut-off adaptor to fuel return line. Turn ignition on. Bleed air out of gauge. Use scan tool to command fuel pump ON. Repeat scan tool command several times until highest fuel pressure is obtained. Slowly pinch off fuel inlet hose. Observe fuel pressure readings. If pressure remains constant, go to step  21. If fuel pressure does not remain constant, go to next step.
  11. Use scan tool to command fuel pump ON. Wait for pressure to build up. Close valve in fuel pipe shut-off adapter connected to fuel return hose. If fuel pressure remains constant, go to step  20. If fuel pressure does not remain constant, go to step  22.
  12. If fuel pressure is greater than 47 psi (3.3 kg/cm2 ), go to next step. If fuel pressure is less than 47 psi (3.3 kg/cm2 ), go to step  15.
  13. Relieve fuel pressure. See FUEL SYSTEM PRESSURE RELEASE . Disconnect fuel return line from fuel rail. Attach a piece of fuel hose to return line and place in an approved gasoline container. Turn ignition off for about 10 seconds. Turn ignition on. Observe fuel pressure with fuel pump operating. Fuel pressure should be 41-47 psi (2.9-3.3 kg/cm2 ). If fuel pressure is as specified, go to step  23. If fuel pressure is not as specified, go to next step.
  14. Inspect fuel rail return/outlet passage for restriction. If any problems are found, go to step  24. If no problems are found, go to step  20.
  15. Recheck fuel pressure. If fuel pressure exists, go to next step. If no fuel pressure exists, go to step  17.
  16. Relieve fuel pressure. See FUEL SYSTEM PRESSURE RELEASE . Use scan tool to pressurize fuel system. Bleed air out of fuel gauge. Wait for pressure to build up. Slowly pinch fuel pressure gauge outlet hose. Fuel pressure should be about 47 psi (3.3 kg/cm2 ). If fuel pressure increases to greater than specification, go to step  20. If fuel pressure does not increase to greater than specification, go to step  7.
    CAUTION: DO NOT allow fuel pressure to exceed 60 psi (4.2 kg/cm2 ) or fuel pressure regulator may be damaged.
  17. Check fuel system electrical circuits. See FUEL SYSTEM ELECTRICAL TEST  article. If fuel pump circuit problem is found, go to step  24. If fuel pump circuit is okay, go to next step.
  18. Inspect fuel filter, fuel supply line and fuel pump strainer for obstructions or fuel pump flex pipe for leaks. If any problems are found, go to step  24. If no problem was found, go to step  21.
  19. Locate and repair vacuum leak to fuel pressure regulator. Test drive vehicle to confirm repairs.
  20. Replace fuel pressure regulator. Test drive vehicle to confirm repairs.
  21. Replace modular fuel pump/sending unit. Test drive vehicle to confirm repairs.
  22. Locate and replace any leaking fuel injector(s). Test drive vehicle to confirm repairs.
  23. Locate and correct restriction in fuel return line. Test drive vehicle to confirm repairs.
  24. Repair problem as necessary. Test drive vehicle to confirm repairs.
  25. Use scan tool to check for any undiagnosed DTCs. If any are found, go to appropriate SELF-DIAGNOSTICS article to trouble shoot DTCs.
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