LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Saab >> 1987 >> 9000 Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Turbocharger >> Operation >> Maximum Boost Pressure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Maximum Boost Pressure

  1. Run hose of Pressure Reading Equipment (83 93 514) from drivers seat to engine compartment. Position pressure checking gauge vertically. Connect hose of pressure reading equipment to connection of vacuum hoses placed beside expansion tank.
  2. Tilt rear seat cushion forward and detach electrical wiring from control unit. Connect test wiring harness (83 94 074) with service box between normal harness connector for control unit and control unit itself.
  3. Set knock detector switch on service box to "ON" position and solenoid valve switch to "ON" position. Depending on type of fuel in tank, engine may knock continually while measurements are being taken. Engine should be at normal operating temperature.
    CAUTION: Test must be performed as quickly as possible to avoid high temperature build-up in brake linings.
  4. On cars with manual transmissions, start test by driving car in 3rd gear at an engine speed lower than 1500 RPM. On cars with automatic transmissions, start test by driving car with gear selector in position "1" at an engine speed lower than 1500 RPM.
  5. Depress accelerator pedal to floor. When engine speed approaches 3000 RPM, apply brakes so engine is held under full load at 3000 RPM. Read boost pressure from pressure gauge.
  6. Once stabilized, pressure reading should be .6 Bar. If boost pressure is correct, remove testing equipment. If boost pressure is incorrect, faulty boost pressure regulator valve, sticking diaphragm push rod bushing, or blocked orifice in solenoid valve hose connection to turbocharger may be the problem.
scientia non olet · About LEMON Manuals