New hpfp housing

So i own a 2012 ms3 I fucked up the bolt of my old hpfp housing and cant take the internals out so I decided to buy a new one. Also bought an autotech hpfp internals. I decided to put the nee autotech to my brand new hpfp housing and slapped it into my car but my car wont start, the engine would start for a sec and it would die on me. When i put my old one back my car started running fine.

You guys have any idea what could be the issue? I just got my car 2nd hand 6 months ago and new to mazdaspeed so I have no clue about hpfp issues.

My mods for my 2012 ms3 are:
Cobb downpipe
Cobb intake
Damond motor sport pcv plate/occ

 

Start by taking the new pump back apart and checking that you did everything correctly