quackaddict86

Ok so I have a 96 cherokee with a 4.0l and 5 spd. I'm have a server issue with hesitation and backfiring under acceleration. A few weeks ago it started almost "loading" up and it stumbles an falls on its face. It threw a code. I don't remember the number but it said fuel system lean. Then it went away.

Recently it started acting stupid upon initial start like it was "loading" up. Let it warm up a little ran fine. Well now it's stumbles and dies when I even try n pull out. If I don't rev the crap out of it and ride clutch it doesn't wanna go!! When I'm accelerating up a hill if I go so far on throttle is pops and farts and falls on its face like I just got tied to a Mac truck. If I back out a little it clears up but I just can't get the jeep to pull. If I gently roll in the throttle it's good till I get so far. If I just jump in throttle it backfires and cracks and bangs.

If I let it idle it "loads" up and is super flat then it was fine. But now it's almost to point of I wanna drive it off a cliff!!!!

It's had always had a slight hesitation at 1800rpm. So within the last year I have replaced tps and iac and its gotten a full clutch setup. Withing last 2 years I've done a full tune up. So my question is.... Is this a bad map sensor issue? Is it not reading I'm putting a load and tryin to accelerate? I don't wanna drop 100 bucks for a sensor and it not be it.

Also I took notice over on passenger side of engine bay back at the firewall directly above where ac goes in there is a little black object that has two large vaccum hoses and a wire connector. This object is like ticking. You can feel it and hear it. I believe the one house goes to manifold below the map sensor. WHat is this and is it working properly?

Thanks soooo much!!

salad

The ticking object is the evap purge solenoid, it's supposed to do that as it releases vapors from the fuel tank into the intake.

When was your last proper tune up?

What does "loading up" mean?

Here's where I would start if I was you:
- check for vacuum leaks
- test the MAP
- test fuel pressure

Writeups for all of the above can be found on here with a search if you aren't sure how.

SoCalxJ4.0

This?? No it should not be ticking at least mine doesnt. But not knowing more, it sounds like an O2 or a sensor. If a 02 is bad, it's going to give wrong info to computer, and computer is going to lean out/ or flood it with gas, depending on readings. I also have a 96 5 speed, just went through some of same issues. I had a bad rear 02 and a clogged cat. I couldn't rev under load over 3k rpm.

SoCalxJ4.0

Hmmm. Maybe I need a new one of those. Lol. Will that give fuel smell in the cabin if its bad?

quackaddict86

When I say "loading up" as in like if it was a carb and it was gettin way to much fuel. As of right now I don't have any cel. I had disconnected the upstream side o2 and didn't seem to change condition. Could that sensor be bad? And yes that is the exact object I'm talkin about haha thanks for responses guys!!

SoCalxJ4.0

Could be. Did you disconnect it? Or leave it plugged in just not screwed into exhaust? If the upstream and downstream are giving the same readings to the computer, it will throw it off. Did you try and plug in a reader again? Just because the CEL turned off, the code may still be stored.