4n6pc

1996 jeep runs great, no leaks at all from any part of the motor, but I started to lose power going up hills. regular everyday driving road incline for PA nothing major. I need to put it in 3 rather than D partway up. mind you it has 189000 miles on it but I really take care of it (I think) is the motor just old or is there something I can check? thanks guys, I love this jeep and plan on driving till it falls apart I hope this doesn't mean that is coming soon....

DFlintstone

Which engine?

schadelh

96 with 4 spd auto. Should be a 4.0HO

Mech17

I would check your fuel pressure. If it's getting low and your engine needs to suck that extra fuel and it's not there, that could cause your problem.

SeriousOffroad

Lifted?
Tire size?
Current axle gear ratio is....?

En.Ki

before mine overheated I was losing power and shifting into 2nd! on some hill/mountains... I put to the fact I just installed 31's after having 235/75's, the day it overheated it was still doing this.. not to steal your thread but I am curious of the answer as well... 96 sport, 5spd man, d30, d35, 2in bb, and I am not sure of the gears in the d30/d35...

SnakeEyes814

I'd try adjusting the kick down cable first. Easy and free, takes about a minute to do.

DFlintstone

Since he is now needing to downshift I have my doubts its the ratio or the kick-down. I'd gap the plugs, change the filters, clean the cap in the kitchen sink. Feel the hubs/brakes for extra heat. I once checked my fuel pressure with a cheap tire gauge....Killed it but sort of worked once!

4n6pc

How do I know for sure what the engine size is? I take for granted that it is what others say (not that I doubt anyone) I really should know for sure. I am no mechanic but I love working on it as a hobby, actually replacing front axle u-joints today. I will check the plugs since I just replaced them a few weeks ago with cap rotor and wires but, I direct replaced them with inexpensive plugs and did not gap them so I am guessing that was a mistake,,,, thanks will let you know if that makes a difference.

Destination XJ

Do you have any lift? Are your tires stock or larger sized? What gears? This all matters so please answer.

keelwheel

I had a similar problem. Turned out to be a plugged catalytic converter.

DFlintstone

X2 on the cat. Don't know how common it is. Once after I ruled out regular maintenance I need to do anyway, I loosened the header pipe flange bolts so exhaust could escape there. BINGO! That was it. "repaired" the cat.

Destination, I think he is saying it was OK before. Also 4npc, if it's an inline 6 it's a 4.0. After the filters and stuff, that's all I got. Fuel pressure. you will need help from one of the resident "Wizzards" on how to turn your key on and off to get it it flash codes on the dash. Good luck! D.

Oh and vacuum leaks are a common problem.

En.Ki

found my issue... after my problems we got it started and let it run for about 45 minutes or so and started hearing a noise... seems my #2 AND #3 cylinders and making a crazy knocking... so replacing my engine and rebuilding the current one are now on my list. Not saying by any means this is your problem but I figured out mine

4n6pc

thanks guys, I replace the entire exhaust front to back 6 months ago could it go bad that fast, and is there a way to find out with out putting a pipe in its place?
En.KI that sucks having to replace your motor, I didnt have time to troubleshoot the problem I spent all day Sat replacing the ujoints on the passenger side front axle,,, what pain that was and worse they didnt have the brute force ones so I took the cheap ones (Forgot the name will post later) they didnt even spin nice and smooth out of the box. got them at advanced auto.

SeriousOffroad

You haven't given any info about your gears, lift, or tire size.

Can't help without knowing that info.