Throttle Opener Diaphragm

Start engine and warm to operating temperature. Turn ignition off. Disconnect vacuum hose from throttle opener control diaphragm and plug hose. Connect a vacuum pump and gauge to diaphragm. Apply vacuum. Start engine. Idle speed should be low. Release vacuum from diaphragm. Idle speed should increase. If diaphragm does not respond as described, replace diaphragm.