Fuel problem???
 

Recently bought a 90 4Runner 3.4 swap and the guy I got it from told me it needed a fuel filter so I replaced it and it still bogs/hesitates when I give it about 35% throttle but I can floor it and it’ll clear up and go good. Anyone have any suggestions to what the problem is? Been thinking FPR,injectors or fuel pump but trying to eliminate everything before I do the damn fuel pump.

If someone dropped a 3.4 in a 1990 I'd double/triple check their work before replacing any components. I'm doubtful a new pump would remedy the issue. You need to find someone who has successfully done the swap and find out what issues they encountered and what steps they took to correct.
I'm kind of forced to speculate, but I suspect the seller spent hours tracking down issues and finally gave up and sold off a project that was never completed to the point of being drivable. Maybe you have more info on the history that would help narrow possibilities.

Best way to test fuel pump and rule it out is to hook up a fuel pressure gauge to it.


While the gauge is on there you will be able to test the injectors too if you suspect one is leaking or clogged. I had a couple that were leaking and clogged and I literally couldn’t go over 50mph in my 3vze.

To test the injectors, prime the pump to get to the fuel pressure your suppose to be at (KOEO). Next get either a power probe or make a homemade one. (just grab another 12v battery from a fish finder or something). Once you have a source of power, then get a stopwatch app on your phone ready. Apply power and ground to the injector and see how long it takes to drain the fuel pressure. then repeat for the rest of the injectors.

If an injector is leaking (or a crush washer or fuel line is leaking, possible internal fuel pump leak too) the pressure will drop without even probing an injector with car off, the pressure will be leaking out.

If an injector is clogged when you probe it, it will take a noticeable amount longer to drain the fuel pressure compared to the rest.

To test FPR first thing to do is hook up vacuum gauge to it and see if it holds vacuum. If it holds vacuum it’s good. You’d be able to tell by fuel pressure reading if it’s bad too, it’ll kinda jump around on readings. when the one on my lincoln went bad it jumped around from about 44psi-53psi.

Good luck on getting it running right!

Runs like crap at 35% (closed loop), runs fine wide open (open loop)... You've got sensor issues.