94 Sputtering Problems over 50MPH Runs Rough, Hot

My 94 Olds 3800 Series I Motor runs rough in town and is worse when accelerating. Idles well. When driving in town, the temp gauge goes over the halfway point and that's when everything goes to hell. It will continue to drive good enough in town, although at stop lights it gets warmer, and it sputters while accelerating from them. When I get to the highway, the whole time I am accelerating it sputters, unless I put the pedal to the floor. For a while, when I leveled out at speed it would run fine, but now I have a really hard time getting the car to go over 50MPH. If I floor it and keep it there it might run 60. The temp gauge goes down on the highway, and sometimes that makes it run a bit better. I can't even think about turning on the air conditioner, because that makes every problem I'm having 2-3 times worse. Please help me!

How recent a tune up here, bad plugs, wires, a bad coil, low fuel pressure can all cause this problem. No quick answer the source of the miss has to be pinpointed and corrected.

Replaced Plugs and wires less then 10K miles ago. Replaced Intake and coils shorty after. New alternator 15K ago. Had the problem very slightly before any of this. Just keeps getting worse. Mass Air Flow Sensor? ICM? Crankshaft Sensor? I don't know, and they are all kinda pricey to just guess at and time consuming.

A full scan will help see if these components are an issue. Test fuel pressure as I said first.

I have a 92 eighty eight that does the same exact thing I was told to check egr valve or coolant sensor