Tranny Or Fuel?!?!?!?

My 1996 SL2 is crazy. I just had the water pump replaced after i got STUCK in chattanooga Tenn. Well, When I am going up a hill, the car will shudder between 1000 and 2000 rpms. It also does this if I try to take off really fast. I thought it was the Transmission and I changed the fluids but it is still the same thing. I haven't done any work to the fuel system other than the usual fuel filter replacement. So what could it be.

what transmission? auto or manual

Just because you changed the trans fluid it doesn't eliminate the trans as the problem. Weak fluid pressure caused by a worn pump can allow the clutch packs to slip.

im going to say its not a fuel issue. its either something up with the trans, possible valve body issue which is a common issue on the autos, or your engine mount is bad.

strange to think it could be just an engine mount, but at the rpms you specified you could be making it under a big load and the engine is just jumping around and due to a bad mount can cause some nasty shuddering. the mount thats almost always the problem is the top mount on the passenger side.