in relation to the crankshaft position sensor, you will need to do a voltage test...first, locate the electrical connector for the sensor where it meets up the connector coming from the PCM...then, check for reference voltage by disconnecting the connectors from each other and probing the ground and "hot" ports (reference voltage should be around 5 or 8 volts depending on the year of the truck)...it it passes that test, then check for variable voltage by reconnecting the electrical connectors and backprobing the ground and PCM sensor signal port (values aren't important in this test, you will need to do a slight engine crank and look for a quick change in voltage, probably will have to have somebody help you with this part)

a Haynes repair manual should tell you the reference voltage value as well as which port is which on the electrical connector

 

You have to unscrew it from the pipe, not just unplug the connector. And you should test the CAD motor with a vac pump.