Throttle body (TBI module) — replacement of parts (Chevrolet Tahoe 1)

Important! It is not necessary to remove and disassemble the throttle body to replace the parts. However, for the sake of clarity, the procedures described assume that the TBI module has been removed from the vehicle.

1. Decompress the fuel system.

2. Disconnect the battery from ground.

3. Remove the air filter, adapter and gaskets.

Fuel Flow Meter/Fuel Pressure Regulator Cover Assembly

Attention! The pressure regulator is located in the fuel flow meter cover. If the flow meter or regulator fails, the entire assembly is replaced.

4. Disconnect the connectors from the injectors.

5. Unscrew the screws (see photo) and remove the lid.



6. Remove any remaining old seals (see photo).



7. Inspect and clean the cap. Do not immerse the cap in solvent as this will damage the diaphragm and gasket of the pressure regulator.

Attention! It is forbidden to unscrew the 4 screws securing the pressure regulator to the cover (see photo), to avoid damage to the diaphragm under the action of the releasing regulator spring.

8. Install the unit in reverse order, replacing the gaskets and seals.

Nozzles

9. Disconnect the connectors from the injectors by squeezing the latches and pushing the connector towards you.

10. Remove the cover with the flow meter/pressure regulator.

11. Pry up and remove the nozzle (see photo).



12. Remove the upper (larger) and lower (smaller) O-rings and injector filter.

13. Remove the steel washer from the injector seat.

14. Inspect the fuel injector filter. If contamination is detected, clean the fuel lines and flush the fuel tank.



15. When replacing, please note that the Model 220 TBI system injectors are not interchangeable with injectors of other systems.

16. When assembling, place the new filter on the injector nozzle (see photo).

17. Lubricate the new lower (smaller) sealing ring with automatic transmission fluid and install it into the flange seat in the injector well (see photo).

18. Install a steel washer into the nozzle (see photo).



19. Lubricate the new upper O-ring with automatic transmission fluid and install it on the steel washer (see photo).

Caution! The washer and large sealing ring must be installed in front of the injector. Do not allow this ring to twist.

20. Install the nozzle (see photo).



21. Install all removed parts.

Throttle Position Sensor (TPS sensor) and idle air valve (IAC valve)

22. The procedure for replacing these parts of the throttle pipe is discussed in Chapter 6.

Fuel flow meter housing

23. Disconnect the connectors from the injectors.

24. Remove the fuel flow meter/pressure regulator cover, gasket and pressure regulator seal.

25. Remove the injectors.

26. Disconnect the fuel lines, remove the sealing rings.

27. Unscrew the nuts and disconnect the fuel pipes from the fuel flow meter housing (see photo). Pay attention to the location of the nuts, which should be tightened in place. The holes of the intake tube nuts are of a larger diameter.



28. Remove the gaskets from the nuts.

29. Loosen the screw and remove the flow meter housing (see photo).



30. Assembly is performed in reverse order. Replace all seals of the disassembled connections.