i have a 1994 wrangler with the 2.5 and it starting to get me upset

it starts fine, but after about 5 min it starts missing ang back fireing so i put a fuel pressure gadge on it and at startup its got about 30 to 35 psi but it losses pressure to 0psi when you give it gas so i replaced the fuel pump did not help so i replaced the aic motor o2,fuel filter, pressure regulater, fuel cell vents, and lines,plus the cap,rotor,plugs,wires,and coil,

this jeep is my main transportation and it been down for about 6 months please help

ive read alot of the other post and checked the stuff that they said but no help