Iv bin having problems with my stang, It's got no power after it warms up and if i try to rev it with a little pedal pressures it stumbles but if i floor it it's ok, it also has trouble starting if its hot i have to turn the key and give it gas and then she fires up. also when im looking at my fuel pressure gauge it jumps all over and if i rev it the pressure goes down. could this be a bad fuel pump or injectors it does not wine or anything like that.