History of Fuel injection:
In the past, carburetors were used to deliver the fuel into the engine of vehicles. Carburetors work on Bernoulli’s principle where essentially as the throttle opens up, air moves faster across the fuel jet drawing more fuel into the intake. However, as emissions requirements became more stringent, carburetors did not give enough control over the amount of fuel injected into the engine. This was problematic because the catalytic converters that were being put on cars to meet the emissions standards require a specific air/fuel ratio to be effective and carburetors are not able to consistently operate in in this narrow range. Because of this, fuel injection became more prevalent in cars, and since 1991, all cars in the United States have been sold with fuel injection. Fuel injectors deliver fuel into the intake port of the cylinder in port fuel injection engines or directly into the cylinder in direct injection engines.
The Bosch system used a normal fuel pump, which provided fuel to an injection pump that was mechanically driven, and had separate plungers for each injector in order to provide a high-pressure injection directly into the engine's combustion chamber.
Chevy's design involved directing inducted engine-air across a plunger (specifically a spoon-shaped plunger) that moved in proportion to the air volume. The plunger, in turn, was connected to the fuel metering system with dispensed fuel to the cylinders via mechanically controlled distribution tubes. Unlike other versions of fuel injection, Chevrolet's system used a constant flow of fuel that was metered from a spidery-looking collection of central injection lines, rather than an intermittent or "pulse" injection used by other developers.
Chevy's system adjusted the amount of fuel flow according to the engine's speed and load, and included a fuel reservoir which was not unlike the float chamber found in a carburettor. In 1958, the first electronic version of fuel injection- a multi-point system with dual 2-bbl throttles, became available as an option on Chrysler products using both Hemi and wedge engines. This technology was jointly developed by Chrysler and Bendix.
In 1982, Bosch introduced yet another design change, incorporating a sensor that could directly measure the air mass flow into an engine, into their LH-Jetronic model. The sensor used a heated platinum wire placed within the incoming air flow, and used the rate of cooling to determine the necessary injection flow. This was the first fully digital electronic fuel injection system, which became the standard approach.
With the advent of the digital microprocessor, it was possible to integrate all power train subsystems, including fuel injection, into a single control module. Today, fuel injection, and specifically electronic fuel injection, the technology for mixing air and fuel in an internal combustion engine, and has become the automotive design standard, almost completely replacing carburettors.
The Bosch system used a normal fuel pump, which provided fuel to an injection pump that was mechanically driven, and had separate plungers for each injector in order to provide a high-pressure injection directly into the engine's combustion chamber.
Chevy's design involved directing inducted engine-air across a plunger (specifically a spoon-shaped plunger) that moved in proportion to the air volume. The plunger, in turn, was connected to the fuel metering system with dispensed fuel to the cylinders via mechanically controlled distribution tubes. Unlike other versions of fuel injection, Chevrolet's system used a constant flow of fuel that was metered from a spidery-looking collection of central injection lines, rather than an intermittent or "pulse" injection used by other developers.
Chevy's system adjusted the amount of fuel flow according to the engine's speed and load, and included a fuel reservoir which was not unlike the float chamber found in a carburettor. In 1958, the first electronic version of fuel injection- a multi-point system with dual 2-bbl throttles, became available as an option on Chrysler products using both Hemi and wedge engines. This technology was jointly developed by Chrysler and Bendix.
In 1982, Bosch introduced yet another design change, incorporating a sensor that could directly measure the air mass flow into an engine, into their LH-Jetronic model. The sensor used a heated platinum wire placed within the incoming air flow, and used the rate of cooling to determine the necessary injection flow. This was the first fully digital electronic fuel injection system, which became the standard approach.
With the advent of the digital microprocessor, it was possible to integrate all power train subsystems, including fuel injection, into a single control module. Today, fuel injection, and specifically electronic fuel injection, the technology for mixing air and fuel in an internal combustion engine, and has become the automotive design standard, almost completely replacing carburettors.