1999 Chevy S-10 No throttle when warm

Runs perfect when cold always idles good but the warmer it gets the less throttle you can give it. When its warmed up you can hold it to the floor and only 2500 rpm. Fuel pressure remains about 54 lbs all the time. Cat is not clogged O2 sensors have been changed MAT, MAP and MAF sensors were swapped to see if they were bad. Things done recently were a new lower intake gasket for a water leak and flex hose blew off fuel pump in tank but this promblem was there before but has got worse. Any ideas greatly appreciated this thing is driving me crazy. Thanks Mopar Chuck PS no codes vin X sure it is a fuel problem of some kind but pressure is good I can squirt a shot of starting fluid in a the air horn while holding throttle wide open its 2500 and it shoots right on up.