Hey Dave,



I have no experience with D-jet personally, but they did use a manifold pressure sensor to determine engine load. I found a bit out about D-jet on these two sites:

http://members.rennlist.com/pbanders/djetfund.htm

http://www.icbm.org/erkson/ttt/engine/fuel_injection/d-jet.html

From what I've read, D-jet was an analog system, unlike newer systems that use a digital board for 'thinking' and a additional board that ran the sensors and actuators.


Lots of cars use MAP sensors, used in whats called a 'speed-density' control system. Before hot wire/film air meters were developed, it was pretty much the only way to determine engine load. Many cars continue to use this system long after the AMM was developed. Some examples include many older GM and Chrysler models ones with TBI (throttle body injection) and carbs, and many Hondas, even late model ones. A more familiar example would be the Rex-Regina system used in many 700/900 series cars. Some cars used a vane type air meter, where a spring loaded flap moved in response to air flow, but this is a variation on the speed density system. The MAP sensor is connected to the intake manifold with a vacuum line.

If you would like to know more, look up 'fuel injection theory' in Google. You'll find lots of info about how both mass air and speed density systems work.

Cheers, Jon