GM 91176135 Throttle Body Assembly(On Esn)

The carburetor or TBI unit used on earlier models is attached to the top of the intake manifold by several bolts or nuts. These fasteners can sometimes work loose from vibration and temperature changes during normal engine operation, causing a vacuum leak. If a vacuum leak is suspected at the bottom of the carburetor or throttle body, a two-foot length of fuel line hose can be used. Start the engine and place one end of the hose next to your ear while probing around the base with the other end. A hissing sound will indicate a leak, but be careful of hot or moving engine components. The air cleaner assembly should be removed, with each disconnected hose tagged with a piece of numbered tape for easier reassembly. The mounting nuts or bolts at the base of the carburetor or throttle body should be located, and any necessary special tools or adapters identified. These nuts or bolts should be tightened to the torque, but not over tightened to avoid stripping the threads.

Agree that the choke cable is free to move, and check the choke bore for accumulation and clean if evident. Start the engine and run and use carburetor aerosol cleaner by spraying it at the bottom of the throttle body gasket, all vacuum hoses and the throttle inlet shaft. Higher idle speed implies a presence of a vacuum leak that can be solved by getting a new base gasket, new throttle body or by correcting the bad vacuum connection. Start the removal procedure by disconnecting the cable from the negative terminal of the battery and empty the radiator. Remove the hose clamps of the intake duct and take it off, then turn the throttle linkage cam anti-clockwise and pull the accelerator cable end plug and separate the throttle cable bracket and put it aside. Concerning the automatic transmission vehicles, take out the kick down cable from the throttle linkage and also the cable brackets from the engine. Remove the breather and coolant hoses from the throttle body and label them, remove the electrical connectors from the throttle position sensor and the idle air control valve. Clamp off the hose connecting to the throttle body, then disconnect the electrical connectors and undo the four throttle body to air intake plenum bolts, then pull off the throttle body and gasket. Throttle body casting first of all should be cleaned properly by means of compressed air, but attention should be paid to the fact that it is possible to clean the throttle position sensor and other parts only by compressed air or a clean soft cloth. The following is the reverse procedure to the removal;-The throttle body is installed and the throttle body mounting bolts tightened to the manufactures recommend torque.