I had to replace the fuel pump on my 126 gas car awhile back. Single pump, but same principle as the dual-pump 126 cars.
In the following thread I list off all items that were changed as well as the pump. From my perspective, you may as well change everything down there while you are at it. These are all fuel system parts.
Ignore the pointer in the thread to the braingears.com web site. At one time you could get just about all of the repair doc needed for a 126 car at this site.
http://www.peachparts.com/shopforum/showthread.php?t=149706&highlight=46mm