My 91 lumina 3.1 will not accelerate past 25 mph, when you press on the pedal it just does nothing, it does not stall it just will not accelerate. It also sometime does this after starting, I will put it in reverse or drive and when you go to accelerate it is like the pedal does nothing and the engine is dying but it does not stall or quit.

First check fuel pressure, if ok look at a blocked cat.

Okay Thank You .