Friday, February 6, 2009

Fuel Injection - Early Electronic Systems

The mechanical fuel injection systems had some serious problems when used in passenger type automobiles and development turned to various types of electronic fuel control. Early systems were produced as early as 1957 for an AMC Rambler Rebel. Chrysler used the same system in 1958 on some of their cars. However as in many new technologies, there were some major problems.

Bosch picked up the patents for this early system and went on to develop several different EFI systems. Their first system was called D-Jetronic, and used on several brands such as VW, Mercedes-Benz, Porsche, Citroën, Saab, and Volvo. The D system was followed by the J and L systems. These devices are considered a speed/density system, using engine speed and intake manifold air density to calculate "air mass" flow rate and thus fuel requirements. The correct air fuel mixture is critical for optimal engine performance and longevity.

An advanced system was introduced in 1982 which used a platinum wire located in the incoming air flow. The wire was heated and then became cooler based on the air flow or air mass being drawn into the engine. This was a better and simpler system than the earlier ones, and became a standard. A significant difference on this Bosch system was that it used a digital microprocessor for control, rather than the earlier analog systems.

Tomorrow we will look at the basic designs that have been used by EFI systems and what is destined to be the next major system.

Comments or E-mail me


Honda Accord Performance Parts

Honda Accord Appearance Parts

No comments:

Post a Comment