-I have a manual 1991 Jeep Cherokee Sport with 114k original miles.

Some context: It is my daily driver. A couple months ago I took it on a 500 mile road trip where I did some pretty intense off-roading on a mountain trail. It worked fine on the trails and drove me 4 hours there and 4 hours back. About a week later, it started having these symptoms:

-Will start up fine and seem okay, but then maybe 15 minutes into driving, it will buck/surge and will hesitate a bit when trying to accelerate; typically in 2nd-3rd gear.
-It has a random misfire.
-When slowing down to idle, it will sometimes almost die unless I give a lot of gas.
-Code through OBD1 light method is Code 14; MAP sensor. Replaced that it got a little better but still random misfire.

We have done the following:

-Replaced 02 sensor

-Replaced distributor cap

-Replaced spark plugs

-Replaced crank position sensor

-Replaced map sensor

-Cleaned out injectors

-Replaced fuel filter

-Replaced fuel pump

-Checked air filter

-Compression test which revealed all within normal limits.

Replacing crankshaft position sensor and fuel pump helped a bit at first, but after about 5 starts and 30 minutes of driving total, same symptoms.
I decided to replace all of the injectors and go from stock 1 hole to 4 hole injectors.

Now, the engine cranks but does not start after installing the new injectors.

I went through the entire process twice; installing new injectors, uninstalling once engine would not start, verified no leftover gunk or o-ring was left inside, and then re-installed new injectors again. Same issue.

The original issue of misfire is still not fixed after all the replacements/tune up steps we did, and now it won’t start.
I have tried to get this thing back up and running for the last 3 months, including scouring the web for similar posts/issues and trying to find solutions.

Any help would be greatly appreciated. Need this beast up and running again!

 

The parts cannon kills another xj.

Ok, with that out of the way.
If it at least started before you changed injectors the obvious diagnostic is to make certain the proper leads are going the proper injectors and that the injector wiring/connectors are all solid. If no joy there put the original injectors back in and see what happens.
As far as all the other sensors you replaced if you kinda replaced them all at once rather one at a time and test no telling which of them was bad out of the box.

I know none of this is very helpful but other than the old " you need fuel/spark/compression to run" and make sure the plug/ firing order is correct don't know what to suggest

I'm assuming you have checked all the basic stuff like fuel pressure, spark, bent pins on all the sensors you replaced..

 

 

Did you clean the throttle body and IAC? Cheap and easy to do...

I agree with the above, the parts cannon was fired way too soon.

 

welp spray a little starting fluid in it and if it kicks over then it is indeed an injector issue still.... but if it doesnt then you may have an issue with the coil, happened to my jeep with a combo of the heat shield rotting away for the injectors. where your original issue lies anyways, perfectly fine until about 20 minutes of driving then it sputtered bad to the point it wouldnt drive. again firing a parts cannon at an issue in your case but hey coil packs are cheap and should be replaced if its original lol mine was cracked and all sorts of bad stuff. take it off and inspect it. if cracked replace as it is probably arcing out on the engine or the bracket that holds it in. mine was cracked but with heat it opened it up just enough to spark out. again tho get it running first, slap the original injectors in it as a baseline since that was the last time it ran. its still stuck on the tune for the 1 hole injectors.