1993 Subaru Justy BaseFACTORY OEM SERVICE PROCEDURE

Boost Pressure

  1. Unplug wastegate solenoid connector. Ensure engine is at normal operating temperature. Disconnect rubber hose from pressure switch. Using a "T" fitting, connect an air pressure gauge. Use enough hose so gauge may be observed from inside passenger compartment.
  2. Measure boost pressure at 4600 RPM with wide open throttle. Normal pressure is 6.2-7.3 psi (0.43-0.51 kg/cm2 ). Reconnect wastegate solenoid.
  3. If boost pressure is too high, inspect rubber hose connecting intake manifold to wastegate valve. Replace hose if defective. If wastegate valve is not operating and remains closed, replace turbocharger. If boost pressure is too low, replace turbocharger.
CAUTION: When testing wastegate valve, DO NOT apply any more pressure than specified. Excessive pressure will damage wastegate control valve diaphragm.
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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