my 98 wrangler runs fine for the first little while, at freeway speed, and then loses power, coughs, and sputters. power slowly decreases, until it goes down to 20 miles per hour. it's not uniform on how long it runs good, sometimes for 20 minutes, sometimes 2 hours. when i stop, i check the pressure in the fuel line, and it's usually full of air. yesterday, i tried letting all the air out until gas came through, but the air ran out, and no gas came thru. same thing happened last year, so i replaced the wire and hose harness coming of the gas tank. would it be gone out again, or is there something else i might check. PLEASE HELP!!