Start the engine and let it idle, then disconnect the vacuum hose between the carburetor and the VTV at the carburetor side. Ensure that the choke breaker linkage quickly returns to its recoiled position by spring pressure. Upon reconnecting the hose, confirm that the choke breaker linkage is pulled back within 5 to 15 seconds. In the case of a warmed-up engine, make sure the choke breaker linkage is pulled back into the diaphragm when the hose is reconnected. With the coolant temperature below 41-degrees F (5 degrees C), start the engine, disconnect the hose from the choke opener diaphragm, and reconnect it. Verify that the choke linkage remains steady and does not move. When the engine is at normal operating temperature, disconnect the hose from the choke opener and observe that the choke linkage returns. Reconnect the hose and ensure that the choke is pulled back by the choke opener. When the engine is at operating temperature, ensure the choke linkage is pulled back into the diaphragm when the hose is reconnected. For models with a manual choke, remove the Air Filter Box and pull the choke knob out all the way to ensure the choke valve is fully closed (horizontal position). Confirm that the choke valve is fully open (vertical position) when the choke knob is pushed in all the way. To adjust the fast idle speed, warm the engine to operating temperature, turn the ignition key OFF, and remove the air cleaner assembly. Then, pull the choke knob out completely. Disconnect the vacuum hoses from the distributor and plug the hose ends. Also, disconnect the vacuum hoses from port S of the VCV for the EVAP and EGR valve and plug both ends. Install a tachometer and adjust the fast idle speed to 1,800 rpm. Push the choke knob in all the way and confirm that the idle speed returns to normal. For idle mixture adjustments, ensure to check the ignition timing, the distributor cap and rotor, the condition of the spark plugs and spark plug wires, and perform a complete tune-up if necessary before making these adjustments. Frequently, problems with the mixture are due to a vacuum leak. After the engine has reached normal operating temperature, set the parking brake and block the wheels. Then, remove the air cleaner and turn the idle speed adjusting screw out as far as possible without the engine running rough. The throttle plate(s) must be as nearly closed as possible when adjusting the idle mixture. Turn the idle mixture screw clockwise until the idle speed drops a noticeable amount. Now slowly turn the mixture screw out until the maximum idle speed is reached, but no further. If it was necessary to turn the idle speed screw in (to keep the engine running) before setting the idle mixture, adjust the idle speed and perform the mixture adjustment procedure again. This will ensure that the idle mixture is set with the throttle plates fully closed, so the engine is drawing the fuel mixture only from the idle circuit.
Posted by ToyotaPartsDeal Specialist 
