How to Clean a Chevy TBI Fuel Injuctorby Troy Lambert
A throttle body injection, or TBI, acts almost like a carburetor, except that instead of relying on jets and vacuum to regulate the amount of fuel entering the intake, a fuel injector, or sometimes two, is used to deliver the correct amount of fuel to the engine. The Chevy TBI is very common on a variety of engines and a number of applications. While cleaning the injector itself is often not considered a do-it-yourself job, there are still steps the home mechanic can follow to clean the injector and the throttle body.
Change your fuel filter, and run a fuel system cleaner through your fuel tank. Use a good industrial type cleaner such as the ones available from 3M or Lucas. Follow the instructions on the bottle to be sure that the cleaner mixes well. In the winter months or during wet weather, run a water remover through as well. This not only cleans water out of the fuel system, it also prevents water from settling in the Chevy injector and causing rust.
Remove the air cleaner to expose the throttle body itself. Disconnect the negative battery terminal. You will be working with a flammable chemical and fuel, and this prevents an accidental electrical spark. Work outside in a well ventilated area
Open the butterfly of the throttle body, and spray the entire area thoroughly with throttle body cleaner. This spray cleaner is available at auto parts stores. Do not use carburetor cleaner, as this will damage the throttle body. Using a toothbrush or small parts brush, clean the varnish and debris from the side walls of the throttle body.
Spray the injector or injectors with throttle body cleaner, and gently clean the exterior and the tip of the injector with the brush. Do not insert any metal objects into the tip of the injector, as this will enlarge the nozzle tip, permanently damaging the injector.
Replace the air filter assembly, and start the vehicle. Your Chevy may stumble or hesitate at idle at first, as the injectors flush our the cleaner and the debris left in the throttle body. Let your Chevy idle for about two or three minutes, and then take it for a test drive.
- Commercial cleaning of injectors is available at local auto repair shops. It involves forcing a liquid cleaner through the injectors at the same pressure that fuel is pushed through them. This is the most thorough cleaning method, but the expense of the equipment necessary makes it impractical for the do-it-yourselfer. These services are often available for a nominal fee.
Things You'll Need
- Fuel system cleaner
- Eye protection
- Basic hand tools
- Throttle body cleaner
- Toothbrush or small parts cleaning brush
Based in North Idaho, Troy Lambert has been writing how-to pieces and historical articles for magazines such as "Woodworking" and "Outdoor Idaho" since 1994. Lambert is also a novelist and has a diverse technical and philosophical education. He holds a technical certification from the Motorcycle Mechanics Institute in Phoenix.