Chevrolet 17112747 Carburetor Asm

The carburetor/TBI is attached to the top of the intake manifold by four nuts or bolts. These fasteners can sometimes work loose from vibration and temperature changes during normal engine operation, causing a vacuum leak. To properly tighten the mounting nuts/bolts, a torque wrench is necessary. If you do not own one, they can usually be rented on a daily basis. Remove the air cleaner assembly, tagging each hose to be disconnected with a piece of numbered tape to make reassembly easier. Locate the mounting nuts/bolts at the base of the carburetor/TBI. Decide what special tools or adapters will be necessary, if any, to tighten the fasteners with a socket and the torque wrench. A torque check of the carburetor or fuel injection unit mounting bolts will help eliminate vacuum leaks in the induction system. Tighten the nuts/bolts to the specified torque. Do not overtighten them, as the threads could strip. If you suspect that a vacuum leak exists at the bottom of the carburetor/TBI, obtain a length of hose about the diameter of fuel hose. Start the engine and place one end of the hose next to your ear as you probe around the base with the other end. You will hear a hissing sound if a leak exists. If, after the nuts/bolts are properly tightened, a vacuum leak still exists, the carburetor/TBI must be removed and a new gasket installed. After tightening the fasteners, reinstall the air cleaner and return all hoses to their original positions.