You almost never see carburetors anymore. Not that I’m complaining — they’re inefficient and while tuning them isn’t that hard, it does take practice because when you get down to it, it’s an art form. Dual carbs are even harder but most drivers (emphasis on the most recent generations) have never had to think about carbs since fuel injection dominated the market from the 80s on. Today fuel injection technology is approaching the complexity of rocket science — the fairly basic job of metering fuel is now layered and intertwined with other engine management tasks like ignition timing, spark advance, emissions control, and even new green initiatives like cylinder shut off and/or stop/start. Most drivers take for granted that a computer monitors and controls a lot of the magic under the hood. Once upon a time though, fuel injection was purely about fuel. And the earliest systems didn’t even use a computer. Shall we jump?

The idea of injecting fuel into an internal combustion engine has been kicking around since the late 1800s — however it was Robert Bosch that history has credited with really exploring the technology and taking it to new heights. The earliest systems were purely mechanical and confined mostly to diesel engines. By the 1920s Bosch’s diesel injection technology was in widespread use commercially, and the first gasoline injection systems (not all designed by Bosch — there were many systems being developed around the same time) were having the kinks worked out — but not for cars. The first applications were designed for aircraft engines, since the end of WWI resulted in planes that were flying higher, faster, and making tighter turns that taxed carbs abilities to their practical limits. Just imagine dive bombing something with a carburetor. You won’t be pulling up.

Between WWI and the end of WW2, R&D into fuel injection technology continued, with several false starts — Alfa Romeo arguably designed the “first” production intended electronically controlled fuel injection system, though none were ever produced for a car that was sold to the public. Then Mercedes, following a long standing tradition of diesel injection technology, made the first application of “direct” mechanical injection for a gasoline passenger car with the 300 SL. The term “direct” here not quite the same as current direct injection –  though it was its great-grandaddy. Chrysler and Bendix jointly developed the first publicly available electronically controlled fuel injection system as optional equipment beginning in 1958. Known as Electrojector, the system proved to be unreliable and unable to cope with underhood conditions, and the patents were subsequently sold to… none other than Bobby Bosch.

Bosch (the company) seemed to have developed schizophrenia at this point — they continued to design and refine CIS (continuous injection system) technology for diesels (and eventually for the first water cooled V-dubs and many other gas powered European cars) while also completely revolutionizing electronic fuel injection. They eventually produced the first factory standard gasoline fuel injection system: D-Jetronic. D-jet came in several flavors and was utilized as factory equipment first on the VW 1600 T3 in 1968 (like the Red Baron!) and was then modified for use on Mercedes-Benz, Porsche, Jaguar, Volvo, Citroen and Saab vehicles. D-jet laid down the ground work and nearly all fuel injection systems can trace their lineages back in some way or another to that system. Descendant systems made various improvements, like adding an air flow meter instead of a pressure sensor, and then finally a hot-wire air mass meter to replace the air flow meter. Other improvements like better electrical connectors, digital computers, and the advent of “closed loop” technology (an oxygen sensor to dial in air/fuel mixture more exactly) made fuel injection more and more reliable until by the 80s the latter dominated the automotive landscape. The fate of the carb was finally sealed.

The current FI landscape today is predominantly controlled by Bosch. Most automakers either use their system or use parts designed by Bosch for their systems. New technologies like true direct port injection are making an already efficient system even more efficient — though there may come a time in the near future where gasoline is not the fuel of choice. Hydrogen injection anyone?