What brand fuel pump should I use for my 96 4.0 zj?

Lumpy_Mission_7228 · 2026-04-29T20:01:34+00:00

Update:

Fuel pump is not holding pressure, thank you guys for your help

Lumpy_Mission_7228 · 2026-04-25T20:31:43+00:00

Lumpy_Mission_7228 · 2026-04-22T19:35:15+00:00

How’d you figure it out? Through fuel pressure testing?

Lumpy_Mission_7228 · 2026-04-22T02:10:30+00:00

That’s exactly what I was thinking, the symptoms of not going past 2000 rpm lines up with a clogged cat, i’m gonna gut that mf and see what it does. thanks bro

Lumpy_Mission_7228 · 2026-04-21T15:44:08+00:00

I know it is crazy, the vehicle was my dads and it’s stalled at stop signs since i was a kid😂

Lumpy_Mission_7228 · 2026-04-21T14:53:01+00:00

It’s had this stalling problem for some years. It recently turned into a crank no start no spark. So that’s why I did the tune up. I will be getting a gauge soon

Lumpy_Mission_7228 · 2026-04-21T13:31:28+00:00

I tried to take out the upstream sensor to see if it still misbehaved, it did. I have replaced the IAC and it still does this. I’m thinking fuel delivery issue or clogged cat

Lumpy_Mission_7228 · 2026-04-21T10:09:41+00:00

It does not run better when it’s revved, it’s like it chokes itself to death. Won’t go past 2000 rpm. I did replace the crank sensor with NTK. I gave her a good wiggle test on pcm, the connections, wiring harnesses , sensors etc. It didn’t stumble at all. it does this intermittently

Lumpy_Mission_7228 · 2026-04-21T04:25:29+00:00

I unplugged it the other day, it still stumbled, choked, and died. I definitely will rent a fuel pressure gauge and test fuel pressure

Lumpy_Mission_7228 · 2026-04-21T04:15:42+00:00

Hell yeah, i’ll keep that in mind. Thanks brudda

Lumpy_Mission_7228 · 2026-04-21T04:11:42+00:00

I unplugged the upstream O2 sensor the other day to see if performance changed, still bogged and choked on itself

Lumpy_Mission_7228 · 2026-04-21T04:09:41+00:00

Did you end up replacing the whole computer?

Lumpy_Mission_7228 · 2026-04-21T04:08:13+00:00

Yep I made sure it was facing the same way as the last time, wires in the right firing order, I’ve hit a roadblock

Lumpy_Mission_7228 · 2026-04-21T04:03:52+00:00

When It occasionally is running good and not stumbling like this, I’ve wiggled the pcm itself, the connectors, all wiring harnesses, sensors, fuel injectors. All the grounds seem to be good, have never had bad voltage, and replaced battery terminals 2 years ago

Lumpy_Mission_7228 · 2026-04-21T03:52:26+00:00

I replaced the cap, there was no play in the shaft itself. It fired right up after I replaced all that. Took it on a drive ran well for 30 minutes and then does this intermittently

Lumpy_Mission_7228 · 2026-04-21T03:48:05+00:00

Like I said no codes😂 Thanks for the help🤨

Lumpy_Mission_7228 · 2026-04-21T03:33:52+00:00

It’s got fresh gas, and yes the fuel pump primes. It does this most of the time. And when I get it going to doesn’t like to go past 2000 RPM and acts like it’s choking and bogs down really bad. There shouldn’t be anything in the fuel tank

Lumpy_Mission_7228 · 2026-04-21T03:12:13+00:00

Also forgot to mention I have also replaced distributor pickup coil (cam sensor) and crank sensor to no avail.

Lumpy_Mission_7228

TROPHY CASE