G 3500 1 Ton Van V8-350 5.7L VIN K TBI (1987)
Idle Speed: Adjustments
Minimum Air Rate - Fuel Injection Only
NOTE:
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This adjustment should be performed only when the throttle body assembly has been replaced. Engine should be at normal operating temperature
before making adjustment.
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The throttle stop screw, used for regulating minimum idle speed, is adjusted at the factory. The screw is covered with a plug to discourage
unauthorized adjustments.
ADJUSTMENT
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Remove air cleaner, adapter and gaskets. Discard gaskets.
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Plug any vacuum line ports as required.
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With IAC valve connected, ground diagnostic terminal (ALDL connector).
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Turn on ignition, do not start engine. Wait at least 30 seconds (this allows IAC valve pintle to extend and seat in throttle body).
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With ignition "ON", disconnect IAC valve electrical connector.
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Remove ground from Diagnostic Terminal and start engine.
Stop Screw Plug Removal
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Remove plug by first piercing it with awl, then apply leverage.
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Adjust idle stop screw to obtain:
500-550 rpm (in drive with automatic transmissions)
600-650 rpm (in neutral with manual transmissions)
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Turn ignition "OFF" and reconnect IAC valve electrical connector.
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Unplug any plugged vacuum line ports and install air cleaner adapter and new gaskets.