By far the best and easiest way to diagnose (or read) the sensors or actuators is a breakout box. There are 2 styles: simple break out and "monitor box". Both units were made by various manufacturers. The simple one is about $550 new. They are available on E Bay typically for $130.
Use the this sheet as to record the values, breakout box values
EEC-IV breakout box
EEC-IV monitor box