I replaced my factory computer in my 90 model 928 with a Motec, and used the factory flywheel sensor, factory HALL effect sensor, and used a GM Throttle Position Sensor, factory water temp sensor, and added a GM air temp sensor. I went this route as the factory system would not do what I wanted to do with my project. I made the harness and used larger injectors, and Ditched the Mass Air Flow sensor and used 2 GM MAP Sensors, one open to the air and one connected to the intake via a vacum line.

My website is currently down but you can find out more @ http://www.928sg.com

Sterling

98 e430
90 928 6.4 liter w/VarioCam