1990 infinity stalls while driving

Because it is a 1990 vintage, an ODBII scan tool won't work. Based on the available parts to replace on that engine, it could be several things, but I can give you one place to start. That engine uses a Mass Airflow sensor. With the car off, key out of the ignition, unplug the connector on the Mass Airflow sensor. Should be right next to the air filter and before the throttle plate. Try starting the car. Newer cars will revert to a default table in the computer memory and ignore that sensor. I hope that a car that old does the same thing. If the car runs considerably better, if it is able to run at all, change the Mass Airflow sensor.