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Fuel Injected Models

CAUTION: High fuel pressure may be present in fuel lines and component parts on some models. Relieve pressure before attempting to open system for testing or component replacement. Do not allow fuel to flow onto engine or electrical parts or allow an open flame in area while testing fuel system components.
  1. For no-start condition, see MPFI and SPFI FUEL PUMP CIRCUIT TEST. To check for proper fuel pressure on running engine go to step 2).
  2. Disconnect fuel pump connector. Crank engine for at least 5 seconds. If engine starts, let run until it stops. Disconnect fuel hose at pressure regulator and install fuel pressure gauge using "T" fitting.
  3. Start engine and check fuel pressure at idle. See REGULATED FUEL PRESSURE table. Increase engine RPM and make sure fuel pressure increases.
REGULATED FUEL PRESSURE

Application At Idle psi (kg/cm2 )
MPFI 26-30 (1.8-2.1)
SPFI 20-24 (1.4-1.7)
Fig 1: MPFI Fuel Pump Circuit Test - Wiring Diagram (Sedan, Wagon & 3-Door)
G118304Courtesy of SUBARU OF AMERICA, INC.
Fig 2: MPFI Fuel Pump Circuit Test - Wiring Diagram (1800 cc Model)
G118305Courtesy of SUBARU OF AMERICA, INC.
Fig 3: MPFI Fuel Pump Circuit Test - Wiring Diagram (2700 cc Model)
G118306Courtesy of SUBARU OF AMERICA, INC.
Fig 4: MPFI Fuel Pump Circuit Test - Flow Chart (Sedan, Wagon & 3-Door) (1 of 7)
G118307Courtesy of SUBARU OF AMERICA, INC.
Fig 5: MPFI Fuel Pump Circuit Test - Flow Chart (Sedan, Wagon & 3-Door) (2 of 7)
G121849Courtesy of SUBARU OF AMERICA, INC.
Fig 6: MPFI Fuel Pump Circuit Test - Flow Chart (Sedan, Wagon & 3-Door) (3 of 7)
G121850Courtesy of SUBARU OF AMERICA, INC.
Fig 7: MPFI Fuel Pump Circuit Test - Flow Chart (Sedan, Wagon & 3-Door) (4 of 4)
G121851Courtesy of SUBARU OF AMERICA, INC.
Fig 8: MPFI Fuel Pump Circuit Test - Flow Chart (Sedan, Wagon & 3-Door) (5 of 7)
G118308Courtesy of SUBARU OF AMERICA, INC.
Fig 9: MPFI Fuel Pump Circuit Test - Flow Chart (Sedan, Wagon & 3-Door) (6 of 7)
G121852Courtesy of SUBARU OF AMERICA, INC.
Fig 10: MPFI Fuel Pump Circuit Test - Flow Chart (Sedan, Wagon & 3-Door) (7 of 7)
G121853Courtesy of SUBARU OF AMERICA, INC.
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