Is there something wrong with my Corsica? Engine? Transmition? What? on 1995 Chevrolet Corsica

When I step on the gas it takes a second to get up to speed. And when I step on the gas pedal I hear a popping sound. Also when I stopped the car shakes. Tonight when I got home I smelt a burning smell. I am worried.

Sounds like the transfer case is done. Need to get this to a shop very soon and get it checked out. If I am right, soon the vechicle will be shaking all of the time when moving and the vechicle will be bucking with a lot of grinding noise at lower speeds. Do you have this noise when in park or neutral or just when in a forward gear.
It doesnt make the clicking sound unless, I press all the way down on the gas pedal but the main things I notice is the slower to get up to speed for that one second and the shaking but it doesnt make a lot of sound when I put it in drive or back up just shakes when I drive reverse or have the car stopped at a light or pulled to side of the road. but there isn't a constant loud sound.
Then this is a fuel to air mix problem. Cheapest way to check this problem is to change air filter and change spark plugs and see if the problem starts to clear up some. Then send message back to me.