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Home >> Chevrolet >> 1985 >> Spectrum L4-91.5 1.5L >> Repair and Diagnosis >> Powertrain Management >> Tune-up and Engine Performance Checks >> Idle Speed >> Adjustments
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Idle Speed: Adjustments


1.0L Set idle speed with all accessories and cooling fan off. Set idle up with lights and heater on. To set fast idle, disconnect and plug coolant hoses at carburetor thermo element and set fast idle cam on index mark. Set fast idle with engine at operating temperature.
1.0L, 1.5L Turbo: Set idle to specified speed. To set electrical speed-up (1.0L), turn headlights on and adjust screw on solenoid. To set AC speed-up (1.0L), turn AC on and adjust screw on solenoid.
1.5L 2V: Disconnect and plug distributor vacuum, canister purge, EGR, ITC, vacuum hoses.
Air-conditioned models equipped with idle speed-up solenoid, turn AC on and with solenoid fully extended, adjust solenoid to obtain specified rpm.
1.6L Nova 2V: Set idle speed to specified value. To set fast idle, disconnect hose from M port of thermo vacuum switching valve. To set speed-up speed (first step), disconnect vacuum hose from rear of vacuum solenoid. Check speed-up speed against specified value. Reconnect hose and disconnect first hose by linkage to check second step speed-up speed.
1.6L Nova, Prizm FI: Set idle to specified value.



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