I am having the same trouble with the fuel pump not seating correctly. I purchased a new aftermarket fuel tank along with the new fuel pump. Oh yeah this is a two door 1998. After messing around with it…trying everything possible to get it to seat properly and almost disassembling the fuel pump in order to grind the spring support/guide rods…this would not have been a good idea. Moving forward I just recently noticed that the aftermarket fuel tank flange(where the fuel pump rubber gasket would sit and seal) is embossed incorrectly which causes a "crinkle" affect allowing for sporadic rises in the circumference of the metal flange. The raised areas were difficult to identify since the defects are only approximately 1/32" to 1/16" however this is exactly enough to prevent the fuel pump from compressing enough to properly install the retaining ring/clip. Its now too late at night slash/morning to try to repair the flange as this will take some metal working and may require hammer or possibly pliers to lightly bend/form the raised areas of flange into a better shape. Any ideas on how to reform this flange would be appreciated…I'm sure glad I didn't disassemble the pump in order the grind the rods because that would not have solved the problem.

 

I think you hit the nail on the head... defective aftermarket tank. Return it. What brand is the fuel pump? Aftermarket pumps often have fitment issues along with insufficient pressure and excessive leakdown, and trouble with fuel level senders, best to avoid them. Use AC Delco or Delphi pump only.

 

cant remember what i was doing a pump in but ran into this issue last year, the angle of the new cheepo fuel pump was different then the old one making it not fit all the way into the gas tank. it does happen.