Looking for some new ideas been working in '93RRC and will start fine and idle fine but when I give it gas starts misfiring. New plugs,wires,cap, rotor. Fuel Pressure at 34-36, base idle good, timing good, clean MAF and throttle body. Did RAVE tests and everything checked good. Getting code 48 after about 10 minutes. Replaced IAC still good code after about 10 minutes.
Any help would be great

 

Code 48 means its a stepper motor