Hi A few weeks ago my r53 wasnt starting , after changing the pump and plug turned out to be fuel pressure regulator. I replaced it with a VW one 3 bar and was starting right away just not acceleration as it should. Now i replaced the vw one with the right cooper s pressure regulator it wont start at all.. installed the vw one again and now it wont start even with it as it was starting before... Any idea what could be ?