Fuel pump

OK, so i have gone through way to much work turning my 89 mj into a 97 xj. My fuel pump is making noise, sounds like its trying to pump a little to hard. the question is since the 89 had a return system, can i fit a pump out of a 97 into the sending unit. i really dont feel like putting a different tank in it, cutting holes in the bed would defeat the purpose, trying to make a relable daily driver that i can put my bike in the back of. So since so much modifcation has gon on i was hoping that i might get lucky and the pump would be the same size?

Well, there were several changes over the years in the pumps.

What are you running for engine control/injectors/etc.?

The 87-95 4.0 would want 31 psi with vacuum to the regulator, 39 psi without. the 96+ would be closer to 49 psi all the time.

I know if you squeeze off the return line on the 87-95 the pressure can spike to over 95 psi VERY fast.

Stock 97 controls, i was stairing at the short term fuel trim on the scan tool and it would apper by what the ecu is trying to do (-33%) that you would be correct with excesive fuel pressure. From what ive been told the 97 non return system has a dump valve in the pump that kicks in at around 48psi. it sounds like the newer pump has a larger diamiter.

That would make sense.

As you are very limited in choices--rarity of MJ tanks, no 93+ MJs, trying to fit the 97+ pump, if doable, would be a good upgrade.

Another option, more expensive, would be to go to an external pump and FPR, something from Holley?

EDIT: I remember now some of your earlier posts on the conversion!

The only thing that scares me about the external is the stupid pump is ecu controled, and my thing is daily driver. Thats why im dumping the idea of the 1-ton full widths. For now. i hope when i can put them under it they haven't rusted to pieces. theres another one, the 89's brake switch runs through the turnsignal switch, the 97 has two different circuits. im trying (mostly just havent had time to go to radio shack) to put a resistor into two diodes that branch off the brake circuit into the turnsignal circuits.
=-<= i think it will work just not sure on how much resistance i need?