Chevrolet TBI Engine: When Was It Made & Which Years Was It Used?

In the 1980s, automobile manufacturers were coming to grips with increasingly stringent fuel efficiency and emissions regulations. Mercedes, for example, turned to turbocharged diesels for better performance. General Motors tried several approaches, and some results were better than others.

Making smaller cars, such as the Chevette, worked well. Millions of them were made. Other attempts, such as Cadillac's V8-6-4 engine, were utter failures. The computing power to turn cylinders on and off adequately was simply not available at that time. Aerodynamics also became important, but not all models changed to a slippery form.

GM also tried different flavors of fuel injection. Chevrolet used Cross-Fire Injection in the 1982-1984 Corvettes, but it was rather complicated. GMC and Chevrolet also came out with a form of Electronic Fuel Injection called Throttle Body Injection (TBI). Instead of emphasizing horsepower, as with Chevy's sports-oriented models, TBI engines went primarily into large vehicles such as full-sized sedans and people movers.

TBI was introduced in stages to full-size sedans and coupes and then to Chevrolet and GMC vans and trucks. In 1985, the 4.3-liter LB4 engine was brought into the line-up. The Caprice got the engine, and performance over the 1982 model year was noticeable. The 1982 Caprice with the base LC3 3.8-liter V6 would go 0-60 mph in 16.5 seconds and was rated at 16.9 mpg, according to Automobile-Catalog.

The 1987 version with the base LB4 would go 0-60 mph in 12.5 seconds and was still rated by the EPA at 20 mpg. While the bigger engine got the land yacht moving faster, it also had a 2.56 final drive ratio, while the 1982 version featured a 2.73 gear ratio. The new, more powerful TBI engine was able to improve acceleration while also improving fuel economy. 

The rollout of TBI engines continued across the larger end of Chevrolet's and GMC's lines. The 5.7-liter TBI engines began arriving in 1987 for the Suburban and other vehicles of that size. TBI engines remained in use through 1995, officially, though some early model year 1996 cars still had them. The L05 was replaced by the famous LT1 engine.

There are three basic types of fuel injection in petrol cars: Single-point, multi-point, and direct. Single-point fuel injection is an earlier system that uses one or two injectors in the throttle body to spray fuel into an intake manifold shared by all cylinders. With multi-point or port injection, each cylinder has a separate nozzle or injector, which is more fuel-efficient and safer — as the break of one nozzle doesn't take down the entire engine, just the particular cylinder. 

TBI was made for a relatively easy modification to a carbureted engine since a fuel injector and throttle body combination can be placed where a carburetor normally sits. It does not require as much computing power that direct injection requires, either.

There is one other advantage to single-point injection, including TBI, that became apparent later, once direct injection became more prevalent again in the 2000s. The fuel flowing through the intake manifold helps keep it clean. Direct injection systems lack this flow, and the resulting buildup can be so difficult to remove that it needs walnut blasting to solve the problem.