1994 Dodge Van Before Change Trans Fluid Everythimg Fine Level Good Now Takes

before i change trans fluid everythimg was fine fluid level is good but now it takes awhile to go in drive and reverse when i do trys to move it ;'it acts like its going to cut off' when i put it in drive or reverse when it do moves and if i take it out of gear and put it back nothing wont move but if i let it set and let fluid cool i can move alittle engine will die down and cut off if i try to hard to move could it be the ttc soleniod'.also when i start up engine idles up then dies down like its going to cut off has new tps and idle control valve