The Bendix Electrojector is an electronically controlled
manifold injection (EFI) system developed and made by
Bendix Corporation
Bendix Corporation is an American manufacturing and engineering company which, during various times in its existence, made automotive brake shoes and systems, vacuum tubes, aircraft brakes, aeronautical hydraulics and electric power systems, ...
. In 1957, American Motors (AMC) offered the Electrojector as an option in some of their cars;
Chrysler
Stellantis North America (officially FCA US and formerly Chrysler ()) is one of the " Big Three" automobile manufacturers in the United States, headquartered in Auburn Hills, Michigan. It is the American subsidiary of the multinational automot ...
followed in 1958. However, it proved to be an unreliable system that was soon replaced by conventional
carburetor
A carburetor (also spelled carburettor) is a device used by an internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the venturi tube in the main meter ...
s. The Electrojector patents were then sold to German car component supplier
Bosch, who developed the Electrojctor into a functioning system, the
Bosch D-Jetronic, introduced in 1967.
Description
The Electrojector is an electronically controlled multi-point injection system that has an analogue engine control unit, the so-called "modulator" that uses the intake manifold vacuum and the engine speed for metering the right amount of fuel. The fuel is injected intermittently, and with a constant pressure of . The injectors are spring-loaded active injectors, actuated by a modulator-controlled electromagnet. Pulse-width modulation is used to change the amount of injected fuel: since the injection pressure is constant, the fuel amount can only be changed by increasing or decreasing the injection pulse duration. The modulator receives the injection pulse from an injection pulse generator that rotates in sync with the ignition distributor. The modulator converts the injection pulse into a correct injection signal for each fuel injector primarily by using the intake manifold and crankshaft speed sensor signals. It uses analogue
transistor
upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink).
A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch ...
technology (i. e. no
microprocessor
A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circu ...
) to do so. The system also supports setting the correct idle speed, mixture enrichment, and coolant temperature using additional resistors in the modulator.
History
The Electrojector was first offered by
American Motors Corporation
American Motors Corporation (AMC; commonly referred to as American Motors) was an American automobile manufacturing company formed by the merger of Nash-Kelvinator Corporation and Hudson Motor Car Company on May 1, 1954. At the time, it was t ...
(AMC) in 1957. The
Rambler Rebel
The Rambler Rebel is an automobile that was produced by the American Motors Corporation (AMC) of Kenosha, Wisconsin for the 1957–1960 model years, as well as again for 1966 and 1967.
Introduced as a stand-alone model in one body style, the 195 ...
was used to promote AMC's new
engine. The Electrojector-injected engine was an option and rated at . It produced peak
torque
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of t ...
500
rpm lower than the equivalent
carburetor
A carburetor (also spelled carburettor) is a device used by an internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the venturi tube in the main meter ...
engine
The cost of the EFI option was
US$395 and it was available on 15 June 1957.
According to AMC, the price would be significantly less than Chevrolet's mechanical fuel injection option.
Initial problems with the Electrojector meant only
pre-production cars had it installed so very few cars were sold and none were made available to the public.
[{{cite web , url= http://www.petersen.org/default.cfm?docid=1034 , first=Leslie , last=Kendall , title=American Musclecars: Power to the People , publisher=Petersen Automotive Museum , archiveurl= https://web.archive.org/web/20111027060937/http://www.petersen.org/default.cfm?docid=1034 , archivedate=2011-10-27 , accessdate=2018-11-08] The EFI system in the Rambler worked well in warm weather, but was difficult to start in cooler temperatures.
Chrysler offered Electrojector on the 1958
Chrysler 300D,
DeSoto Adventurer,
Dodge D-500, and
Plymouth Fury.
The early electronic components were not reliable in an underhood environment and were not easily modified as engine control requirements advanced. Most of the 35 vehicles originally equipped with Electrojector were retrofitted with 4-barrel carburetors. The Electrojector patents were subsequently sold to Bosch.
Bosch developed their ''
D-Jetronic'' (''D'' for ''Druckfühlergesteuert'', German for "pressure-sensor-controlled"), from the Electrojector, which was first used on the
VW 1600TL/E in 1967. This was a speed/density system, using engine speed and intake manifold air density to calculate "air mass" flow rate and thus fuel requirements. This system was adopted by
VW,
Mercedes-Benz
Mercedes-Benz (), commonly referred to as Mercedes and sometimes as Benz, is a German luxury and commercial vehicle automotive brand established in 1926. Mercedes-Benz AG (a Mercedes-Benz Group subsidiary established in 2019) is headquarter ...
,
Porsche,
Citroën
Citroën () is a French automobile brand. The "Automobiles Citroën" manufacturing company was founded in March 1919 by André Citroën. Citroën is owned by Stellantis since 2021 and previously was part of the PSA Group after Peugeot acquired ...
,
Saab, and
Volvo
The Volvo Group ( sv, Volvokoncernen; legally Aktiebolaget Volvo, shortened to AB Volvo, stylized as VOLVO) is a Swedish multinational manufacturing corporation headquartered in Gothenburg. While its core activity is the production, distributio ...
. Lucas licensed the system for production in
Jaguar
The jaguar (''Panthera onca'') is a large cat species and the only living member of the genus ''Panthera'' native to the Americas. With a body length of up to and a weight of up to , it is the largest cat species in the Americas and the thi ...
cars, initially in D-Jetronic form, before switching to L-Jetronic in 1978 on the
XK6 engine.
References
Fuel injection systems
Embedded systems
Power control
Engine technology
Automotive technology tradenames
Bendix Corporation