One of the key modern automobile innovations is the invention of fuel injection. Carburetors were used for decades, with great success, but when it comes to clean-air and precise air-to-fuel ratios, they were often unpredictable at best. The history of fuel injected automobiles dates back as far as the early 1900s.
Initially, mechanical fuel injection was used exclusively in aircraft engines. This began in 1902 and continued through World War I and World War II.
In the 1940s racers and hot-rodders began to experiment with mechanical fuel injection. It was used primarily in endurance races and with land speed record seekers on the salt flats.
By the 1950s Mercedes-Benz had embraced mechanical fuel injection, in the form of Bosch direct injection. In 1955 Mercedes-Benz outfitted a 300SLR with the Bosch direct injected aircraft engine. Stirling Moss drove it to victory in the Italian event known as the Mille Miglia; a 1000-mile endurance race held from 1927 to 1957.
Unbeknownst to many car enthusiasts, Chevrolet introduced the 1957 Corvette equipped with a mechanically fuel injected 283-cubic inch V8. See the image, above.
During the 1960s mechanical fuel injection was used sparingly in the U.S., almost exclusively in racing applications. The primitive design for metering the amount of fuel delivered was unsuitable for street applications.
Near the end of the 1960s European automakers began experimenting with mechanical fuel injection for production vehicles. Porsche, Peugeot, Audi, BMW, Aston Martin, Triumph, and Volkswagen were included among the manufacturers who outfitted select models with Bosch Jetronic mechanical fuel injection. This continued until the mid 1970s.
Bendix, an American corporation absorbed by Honeywell in 1983, was responsible for the first electronic fuel injection (EFI) system offered in a production vehicle. In 1957 the American Motors Corporation outfitted the Rambler with an electronic fuel injection system, called the Electrojector, on a 5.4-liter V8. The Electrojector was very temperamental especially during cold weather conditions and failed miserably during pre-production testing.
By 1958, American Motors had worked out some of the glitches with the Electrojector system and Chrysler opted to offer it on the 300D, the DeSoto Adventurer, the Dodge D-500, and the Plymouth Fury. These are considered to be the first production electronic fuel injection automobiles. Due to the primitive design and construction of early EFI components, only thirty-five units were ever actually delivered to consumers. Most were eventually converted to four-barrel carburetors and the Electrojector patent design was sold to Bosch.
By 1967, the Electrojector had been developed by Bosch into a marketable EFI system. The evolved Bosch design was called the D-Jetronic (D signifying “druck” which is German for pressure). Again, European automakers jumped on the idea. Citreon, Saab, Volkswagen, Mercedes-Benz, Volvo, and Jaguar all produced automobiles with, not only the D-Jetronic system, but also the succeeding K-Jetronic and L-Jetronic systems into the mid 1970s.
The 1975 Cadillac Seville was equipped with an EFI system developed by Bendix. It bore great similarity to the Jetronic systems offered by Bosch. This system utilized an air flow meter, atmospheric pressure sensor, and engine temperature sensor to determine the rate at which fuel should be delivered. Air flow varied, increasing as the throttle was opened and vehicle speed was increased and decreasing as the throttle was closed and vehicle speed decreased. Fuel was delivered accordingly.
Motorola, an American based company, began producing the first Electronic Engine Control Modules for fuel injected engines in 1980. Called the EEC-III, this system was offered in North American Ford Motor Company Products. Having maintained and repaired these systems, I can say that they were relatively primitive compared to today’s OBD-II systems.
By the mid 1980s automakers were in the process of discontinuing the use of carbureted fuel delivery engines. Partially because of stricter U.S. emission guidelines and partly because of improved drivability for consumers, nearly every major automaker made computerized EFI the primary method of fuel delivery for all models. Individual automakers used their own computer controlled systems which required dedicated diagnostic equipment.
The inception of the On Board Diagnostic II (OBD-II) System came in 1995. Less than half of all vehicles manufactured in the U.S. were fitted with the new system in 1995, but Federal mandate ensured that all 1996 models were OBD-II certified. OBD-II offered precise fuel delivery, tedious engine monitoring, and universal diagnostic connectors.
Be on the lookout for the next article in this series on the BestRide Midnight Oil Blog, which deals with modern computer controlled electronic fuel injection systems. We will take a look at the individual components involved and their function in Top Automotive Innovations: Electronic Fuel Injection.