TBI TBI Bolt Tightness Check (3.1L Engine)

1. The throttle body with injector is attached to the top of the intake manifold with three nuts. Due to vibration and temperature changes during normal engine operation, they sometimes turn away, and this causes air leakage.

2. If you suspect there is an air leak at the bottom of the throttle body, use the rubber hose as a stethoscope. Start the engine and place one end of the hose near the ear and run the other end around the base of the throttle body. If there is a leak, you will hear a hissing sound (be careful, there are hot and moving parts on a running engine).

3. Remove the air filter (see chapter 4).

4. Install throttle body studs (see illustration).



5. Tighten the nuts securely and evenly. Do not overtighten as the threads on the studs may break.

6. If leakage persists even after tightening the nuts, remove the throttle body and install a new gasket. More information on this subject can be found in chapter 4.

7. After tightening the bolts, reinstall the air filter and return all hoses to their original position.