91 grand caravan few problems

To start off with engine cold it starts up fine and while you go down the road it will not acc fast at all like something is holding it back this is floored. Now once the motor warms up it will get up and move just like it should. Then when you park it while warm and try to start it will just crank and crank for awhile before it will start. And i noticed the tranny shifted a bit hard. I own 3 of these all in a close year range. Fuel pressure regulator is my theory. Iv never heard of a fuel pump not putting enough pressure out whenever it wants it either works or it dont. So suggestions?