Cars with Idle Air By-Pass Adjustment

On cars with parking brake vacuum release, disconnect vacuum diaphragm line at diaphragm, then connect vacuum gauge to line. With engine at normal operating temperature, transmission in "N", choke valve fully open and carburetor on slow idle speed (throttle valves fully closed), connect a tachometer to engine. Place transmission in "D", then adjust engine to correct idle speed as indicated in "Specification Table", using the idle air by-pass screw (idle speed adjusting screw on throttle body). Turn one idle mixture screw until highest engine RPM and highest vacuum are obtained at the same time, then repeat this operation with other idle mixture screw. Check and reset idle speed. Repeat idle mixture adjustment until turning the idle mixture screws will not increase engine speed and where the smoothest idle is produced.