[fourfourto]

I would start simple.

#1 Clean flap in air intake with fuel injector cleaner(dont use carb cleaner)follow directions on can.(this is a maintanance thing it couldnt hurt)

#2 make sure high idle controll for a/c isnt on all the time.
to check run car turn a/c on look at tach ,rpm's should go up.
turn air off rpm's should go down.
If it does nothing it could be stuck on? Easy to check and couldnt hurt.

#3 check linkage on gas peddle and under hood at throtle body,clean with fuel injection cleaner and Lube with spray couldnt hurt maitanance thing.
Also check your throttle cable at the same time and lube if posible.

#4 Could be trans ? check with a mechanic

#5 lift up battery and slip another van under it

Good luck