2000 Chrysler Sebring Feul pressure

I recently had a mobile mechanic come out to my house to dignose my vehicle because it would not start. He checked the feul pressure and found that I was only getting about 10 psi. So I went and pulled a feul pump off of a 1996 dodge avenger and installed it. Now where he disconected the line to check the pressure, the part in between the throttle and the windsheild wiper fluid resavoir, is leaking when I turn the key and still no start. Could this leak still cause the engine to not start? And I have tightened the crap out of it and still cant get it tight enough. Any sugestions on what to do? Thanks for all help.