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Home >> GMC >> 1987 >> Forward Control 6.2 J, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Fuel Injection System - 6.2L Diesel >> Adjustments >> Idle Speed
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Idle Speed

  1. Set parking brake and block drive wheels. Warm engine to normal operating temperature and install Tachometer (J-26925). Adjust low idle speed screw on pump to obtain curb idle speed. See Fig 1.
  2. Remove connector from fast idle solenoid. Run an insulated jumper wire from battery positive terminal to solenoid terminal to energize solenoid. Open throttle to ensure plunger is fully extended.
  3. Adjust fast idle speed by turning plunger hex head. Turn off engine. Remove jumper wire and test equipment. Install fast idle solenoid connector.
Fig 1: Idle Speed Adjustment Energize solenoid when adjusting fast idle. Courtesy of General Motors Corp.
G11498
IDLE SPEED (RPM)

Application Curb Idle Fast Idle
6.2L 650 800
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