Ok so on my 94 my air blows super cold and works great.. until i accelerate... When i get on the pedal the air blows up to defrost and wont come back to regular vents until i let off of the pedal. I'm assuming its a vacuum leak somewhere but i dont know if there is a specific place i should look? when i searched i found that someone was told to check their evap canister and mine looks good. So any suggestions?

 

You're going to have to check you're entire vacuum system. The best place to start is at the vacuum ball. Not 100% sure if the 94 has the ball located on the passenger side behind the front bumper. Anyways start from there and make sure that you have no cracks in the ball then just fallow all the lines. That would be the best way to do it that way you can also repair any worn hoses before they brake.
Hope this was some help.
Good luck.

 

X2, I bet he does. Might have a large line and a small. The small one from the vacuum reservoir bottle that goes in there below the coolant expansion bottle, I think provides the "power" to the vacuum motors that control the vents. (diaphragms)

OH! You have an open system, I mean "coolant overflow reservoir"

I think mice ate some of mine in a rude place