Rough idle, tried everything

Hello everyone, I have a 94 xj 4.0 HO AW4 that is having a rough time idling. It runs fine for about 1 minute then just sounds really choppy like it's cammed. I have thouroughly cleaned the TB and IAC . Replaced the TPS, air intake temp sensor, coolant temp sensor, map sensor, fuel pressure regulator, fuel filter and some cracked vacuum lines. I've reset the computer and now it has a hard time starting. I have to pump the gas to get the dam thing to start. It idles rough and if it's in gear and I barely have my foot on the gas there's a lot of hesitation. The plugs are also very white and crusty, I gave them a good cleaning since they were just replaced. It drives fine under throttle. It's just when the throttle is barely open it hesitates. I'm assuming it's fuel I'm just not sure it's injectors or fuel pump. Please help.

Seems like you have an issue with fuel pressure. Ghosting of the plugs tends to mean not enough fuel. This may be caused by a leak in the lines. When you fix the issue its likely it will not run right without a new set of plugs.

You can check the fuel pressure with a gauge to
confirm a fuel problem. I suspect the fuel pump is
bad or there's a split in the pump output rubber
hose inside the tank. Luckily you can service the
pump and hose without removing the tank.

Well I checked the fuel pressure. 11 psi with key on engine off. So I'm gonna get a new fuel pump and see if that fixes the issue. The hard start only happens sometimes. They jeep also sat for a year so there's that to consider as well.

Could also be the FPR, but I forget what year they moved it to the fuel pump. It use to be on the fuel rail starting with Renix, and the first few HO years IIRC. By 96 it changed I think the fuel pump in the tank.

https://www.google.com/search?q=199...4+jeep+cherokee+Fuel+Pressure+Regulator+image


Looks like the 94 still had the FPR on the fuel rail!!!! It is a check valve and fuel pressure regulator. Also the output hose inside the fuel tank goes bad with age. The pump may be OK since you have flow and some pressure.