Built the cable to connect computer to car (92 camaro 305 TBI) as per schematic on Win ALDL site. Attached cable to car and computer, started computer, started car and launched Win ALDL program. One column of data appeared on raw data screen. Also only one column of data on interpreted data screen. Checked com port for correct one and correct speed. Tried the 10K resistor between pins A and B on ALDL connector same results. Values were posted for everthing except RPM amd MPH. Car was in park idleing so 0 mph is expected. Shut the car off but left it in the on position. Several more columns of data posted. Why is data no logging while engine is running? I am out of ideas.

 

A reexamination of the cable revealed transistor was installed backwards. Transistor reveresed. Everything working now!