1993 Ford Probe 2.5l 89,000 miles computer problem

I have a ford probe that misbehaves when warming up. Typically it starts ok but after a minute or two will rev upto 3000 rpm. If I hit the gas while its doing this it sometimes cuts out. Once the car is completly warmed up the problem goes away. If I leave the car to partially cool down for an hour it may not start and smells of gas. Have replaced the MAS and throttle body to no avail.
Could It be the computer? I have been told that there was a problem with the computer in the 93 model that caused it to incorrectly report an 02 sensor problem. If I replace the computer can I use one for a 94? Any thoughts on what may be causing the car to behave this way would be much appreciated