Hey folks,
Upgrading my 88 2.5 TBI YJ to a 94 4.0 MPI.
What do I need to do with the fuel pump to handle the added pressure and volume of the 94.

I plan on keep the 88 15 gallon tank and sending unit. I figure that there is a simple pump swap that will handle the demands of the 4.0

Thanks

The 94 4.0 L pump is definitely but more because of going from TBI to MPI. I swapped my 4 banger MPI to a 4.0L MPI and I did not have to swap pumps.

so when I replace my 94 2.5L with a 4.0, I won't need to replace the fuel pump? What if that 4.0 is really gonna be a 4.6?

Sorry I was not clear, going from TBI to MPI you WILL have to replace your fuel pump.

No the 2.5 pump will not work. If you look in the back of the parts book you will see listing for pump output.

I used a late model Mustang GT pump. Plenty of flow and pressure. fits the 4 cylinder sending unit with little modifacation. Course you have to run an adjustable fuel pressure regulator.

Set my 4.85 stroker up this way.

Sorry to hijack...

Course you have to run an adjustable fuel pressure regulator.

Definately planned on that. What years Mustang? I haven't read anything about that. More info?

Thanks!