Now see, I have this weird problem. And it's starting to get very annoying. If I need to get some quick acceleration (aka pedal to the metal acceleration) my jeep likes to bog and not accelerate. It sounds like it's trying as hard as it can, it down shifts and tries to bring up the RPMs to accelerate but then it just doesn't go and I can hear the engine struggle. I have absolutely no clue what the problem is. I originally thought, "Hmm, maybe it just needs a tune-up" so I did that, but it still has the same problem, now I'm starting to think maybe the fuel pump is dying on me. It has no fuel filter for me to replace so that is out of the question. Other than that I can't imagine what else it could be. Can anyone help? Thank You!

'97 XJ Sport 4.0L

 

checking fuel pressure would help you out, also consider throttle position sensor. it might be worth $50 to pay a reputable shop to run a diagnosis, they can test the tps, fuel pressure and things like that, instead of guessing on parts.

 

my Xj seems to do the same thing but only after a day of mudding. Almost like water has gotten somewhere is doesn't belong usually i let her dry out and the next day runs fine

 

Could be a vacuum leak somewhere? and why the hell don't you have a fuel filter? that's probably the first problem! lol

 

i have the identical issue on my '86 2.5L TBI. We should join forces to find the problem haha

https://www.cherokeeforum.com/f2/2-5l-tbi-sputtering-acceleration-11597/

 

see my 4.0 does that, ill ride her on the trail and she will do great all day then on the ay home it seems like i can't get over 2k in drive and i have to basically go up through the gears manually. I park her and the next morning all is good. I was thinking it is because I am getting the distrubtor cap wet but hasn't thought of the FPR... Hmmm might have to change that next and see what happens.

 

tps, clogged cat, misgapped plugs, map sensor, fuel pressure, restricted air intake/airbox, oxygen sensor, IAC.

does it idle fine, will it rev up in park?

might have something to do with the transmission/tcu, maybe engine computer....

 

revs no problem in park. can go all the way to the redline if i wanted to. I was thinking and this is just me thinking and reading other forums that the process of elimination would be fuel filter, FPR, and finally fuel pump. Oh maybe i should just go ahead and do all 3. it is a 1990 with 200 + on her.

 

does yours also have a stronger exhaust smell than normal? i mean that its noticeable ...

 

had somewhat the same prob.. fell on its face just bout everytime i took off. put a jy computer in it...threw an upstream o2 sensor code... then threw a cat gone bad code. changed it all including the downstream o2 and it hauls now!!! worth a shot... but i would def check fuel pressure b4 i went any further!!!

 

edit- cant read. is it throwing a code? also, what kind of plugs are you running?

 

if revs up in park it could b youd transmission tcu

 

mine rev's up fine in park, also there is a leak from my gas tank right around the area where the fuel pump is inserted into the tank, but if i romp the gas, the damn thing just craps out and refuses to get up and go. and sometimes ill turn it on and it hesitates as if i ran out of gas, but if i let it sit for 15 mins, it fires right up, if i try to start it too soon, it will act as if there is no gas getting to the engine, also i get completely awful gas mileage, about 9-10 mph, and yes there is more, when my fuel guage gets to around 1/4 tank, the car starts putting like im out of gas but it only does it for a min or two and if i dont step on the gas hard and almost coast the jeep acts fine till i fill her up. the funny thing is, all these symptoms started at the exact same time. everything is directly related to the fuel supply so i have reason to believe that the fuel pump might have something to do with it. and as far as the fuel filter, i looked all over and no one sells any kind of a fuel filter for my jeep, 97 XJ Sport, everyone says it is non serviceable and that the strainer attached to the fuel pump itself is used instead. confuses me because then i have other people saying theirs is under the car, but if i can't get a filter and i don't see a filter, im totally confused.

 

also i just did a full tune up, spark plugs, distributor cap, cables, air filter, all that jazz, no difference at all.

 

FUEL PRESSURE???