Can you very slowly depress the gas pedal and get it to rpm higher? Is the idle OK? I would have thought TPS as that's the sensor that tells the computer to give it a shot of gas when depressing gas pedal.

Maybe try using starter fluid to give it a shot as you open the throttle, see if that helps. If so I'd still look to TPS.

92 Montero LS 3.0L V6 Auto, Stock, Original owner, 185,800K miles