Where is the fuel pump control module located?

If I may I would like to tell you what it's doing and not doing. This issue with my wife's 2011 Lincoln MKZ started a little over a month ago. When it was idling the RPMs would drop briefly and then go back up to normal and then it would drop down again briefly and go back up to normal and it kept doing that so I replaced all the fuel injectors I replaced the spark plugs and the coil pack at first it seemed like it was running a lot better and then it wouldn't start the first time you turned over the key it would just crank and then you turn off the key and then you tried it again and then it would start and did that for a while and then about 2 weeks after this started happening we were at Burger King and it just died out wouldn't start back up it would just crank so I had it towed to my house now it just cranks and won't start so I took out the air cleaner and sprayed the carburetor cleaner in it and left it off try to start it and it started right up it ran for about 30 minutes and then it just like choked itself out it just shut off and now it's back to not starting again just cranking and I don't know what the heck the problem is but it's really frustrating.