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Home >> Plymouth >> 1990 >> Laser Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Emission Systems & Sub-Systems >> Fuel Evaporation >> Purge Control System Inspection
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Purge Control System Inspection

  1. Disconnect Red-striped vacuum hose from purge control solenoid valve at throttle body. Plug throttle body fitting. Connect a hand held vacuum pump to Red-striped vacuum hose. Plug fitting at throttle body from which Red-striped vacuum hose was connected.
  2. With engine cold and coolant temperature is less than 140°F (60°C), start engine and let idle. Apply 15 in. Hg vacuum. Check that vacuum holds.
  3. Increase engine speed to 3000 RPM. With vacuum maintained at 15 in. Hg vacuum should still hold.
  4. Warm engine until coolant temperature is greater than 158°F (70°C). Within 3 minutes after starting engine increase engine speed to 3000 RPM. Using hand held vacuum pump, try applying vacuum. Check that vacuum does not hold.
  5. Reduce engine speed to idle. With engine idling, apply 15 in. Hg vacuum. Check that vacuum holds.
    NOTE: When performing next step, if altitude is greater than 7200 feet, or intake air temperature is greater than 122°F (50°C), vacuum will leak continuously.
  6. After 3 minutes have elapsed from starting engine, increase engine speed to 3000 RPM. Apply 15 in. Hg vacuum. Vacuum should hold momentarily, after which it will leak.
  7. If purge control system does not function as described, perform individual component testing.
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