My 95 olds cutlass supreme runs fine etc until I get up to 50-60 mph at 2000 rpm when it will run rough, like its not getting enough fuel or spark.
I changed out the plugs and wires to no avail.
Is there some kind of overdrive sensor??
Any suggestions?

Btw. It runs fine at2000 rpm at any other speed.

normally some kind of ign, problem. whens the last time the plugs/wires were changed? check coils for corrosion?