• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

88 cherokee 4.0L 4x4 hesitation, please help

P

phat87mazdarx7

NAXJA Forum User
Location
kernersville, NC
I've searched and searched for weeks several forums and nothing has worked so I joined here to see if anyone can give me some pointers..

I just recently bought a 88 cherokee for 400 bucks with 183k, it had a brake issue where it was locking up the drivers rear wheel(parking brake equalizer was sitting in the drum loose) so new shoes, new hardware kit, brake adjuster kit(none of it was there, lol) and new springs for the bar, and new parking brake cables. anyways I've got about 800 in parts in this thing and took it for a ride and boom, death wobble, fixed the drag link and the tie rod on it, and everything else was tight, and its better but I still had looseness on the actaual steering column shaft u joint, so I gotta fix that with a used one from the junkyard this weekend. Im assuming that should cure my death wobble. Right??

then my other issue... This car was never maintained Im assuming, so... It recieved a full tune up, Plugs(gaped at .30 or whatever it said under the hood), plug wires, cap, rotor button, di-electric grease on all the terminals, a new(used) injector... one injector wasn't firing so I pulled them all out cleaned them all wiping them with carb cleaner then took a 20oz bottle and filled it up with fuel injector cleaner drilled a hole in the cap and stuck a fuel line in it and attached it right to the injector and squeezed and gave them power(some sprayed weird but cleared up shortly) and back flushed the injectors too. and put it all together with new o-rings and vasaline.. it runs like a freaking top now, sounds great and pulls hard!!!! till you drive it, then it wants to pop in the intake and like stall no misfire I dont recall but definitely runs bad.. so I pulled the cap off the rail and pushed the bleeder valve and really low pressure.. so new pump and sending unit(since the gauge didnt work) I pulled the old one out.. its a rusty nasty mess.. and the fuel is even brown.. so cleaned up what I could feel in the sump and put it all back together.. and it runs great and drives great now, until it starts warming up. then the hesitation is back and it wont move out its own way and will barely put up a hill... I saw a few people mention the O2 sensor since other people had issues after warm up, so I unplugged it to run in open loop, took it for a drive, and ran like normal then when it warmed up, hesitation was back. so its not the O2(though I'm sure its probably never been changed like everything else on the jeep) but I'm tired of spending money and still cant really drive it.. any one have any ideas??

Its an 88 cherokee 4.0 automatic 4x4, when i got it I noticed it had the wrong radiator(it had a radiator cap) so from info from this forum and others I decided to completly trash all the old stuff and upgrade to the 92+ style so i got rid of the pressure bottle thing and replaced it with a overflow from the auto parts store new radiator cap as the old one was pushing water out the overflow(bad spring), put new heater hoses and got rid of the leaking heater valve, got a newer water outlet with the sensor since it had no sensor attached(since its supposed to be on the radiator) and universal fan hard wired was trashed for a used stock one, and everything was extended and wired up and fan works great(but it has never got hot enough to use it, runs about 200-205) it has a brand new fuel pump with the sender(previous one didnt build enough pressure and whined really loud) new pump builds the pressure(visually inspected from the bleeder on the rail) but it whines pretty loud and is annoying too :/ the exhaust was a hacked up mess, found a good used stainless looking one in the junkyard(muffler back) and its running catless right now(sounds good :D) engine wise i cant think of anything else but heres the list of everything I've put into it:

radiator cap 5.99
overflow bottle 9.99
5/8 hose 4.17
5/8 hose 4.17
3/4 hose 6.46
flush kit 3.99
idler pulley 15.99
1/4 screws 3.29
valve cover gasket 5.99
water outlet gasket 2.29
spark plug wires 22.69
spark plugs 16.44
distributor cap 12.99
dist rotor button 11.99
thermostat 7.99
brake adjuster L 9.49
brake adjuster R 8.59
hardware kit 8.09
u-joint 13.09
front pads 12.99
rear shoes 24.49
oil for rear end 11.98
engine oil filter 0
enigne oil 12.97
silicone 7.49
radiator fan 23.2
wiper arm 4.05
thermostat housing 5.63
visor clip 1
enviro charge 2.35
Brake parts cleaner 7.41
Lugnuts ebay 15
parking brake cables 21.98
parking brake springs 1.69
overflow hose 4.95
pvc valve elbow 2.59
pvc grommet 3.29
nuts for bumper 3.29
injector seals 4.49
blower motor 28.99
blower motor resistor 23.99
muffler 14.01
antenna 3.28
bumper brackets 13.64
bat tire good aluminum rim 20.33
dome light cover 1.35
seat belt connector 4.28
exhaust pipe 20.97
hanger 2.99
speakers 25.76
tires 40+10 gas 50
tires mount+balance 52
fuel pump 104.09
drag link 24.29
tie rod end 15.59
oil 12.97
gas treatment 1.57
fuel injector cleaner 1.88
dome light 3.97
foot light 3.97
radio connector 9.72
driver wiper 4.97
rear wiper 4.97

Subtotal 794.11
Tax 55.5877
Total 849.6977


does anyone have any ideas what this hesitation could be or what and how could I check stuff, does the knock crank and cam sensor work like the O2?? unplugg it and it just bypasses that system but will still run. I just need to get this jeep on the road.
 
I once forgot to plug up my sync sensor and ran it for six months that way and never noticed any difference. My guess is it isn't essential. :)

Mine would buck in mid RPM range. It has happened at various times for various reasons.

Once my ballast resistor was in the process of melting down, it wasn't bad yet, but definitely wasn't working like it was supposed to.

I had an iffy ground to my TPS, that was an intermittent thing.

CPS going south. You can ohm test it, if the resistance goes up drastically, like 50 ohms. when it is hot, this may be your issue.

The harness for my O2 sensor (and the engine temp sensor for the ECU and the knock sensor) was melting on the exhaust manifold. No telling what kind of info it was sending to the ECU.

Best bet is to follow Cruisers recommendations and read the Renix files, check all the sensors, check the grounds and clean all the connectors.

And I almost forgot, I was also having some issues withe CPS wiring, once it was cooking on the exhaust manifold and another time it was picking up a lot of resistance between the CPS connector and the ECU.

Once I got the bugs worked out, the Renix runs fine and idles like a metronome. It just takes a lot of perseverance. I feel especially good because the local Jeep dealership gave up on it. LOL
 
I have a 90.

Each Fall, when the weather cools, I do all the connectors--clean and treat with dielectric grease. Now, mine is 23 years old and I have had to replace a number of connectors over the past couple of years. Some have simply broken--age and heat--and some have simply corroded despite my efforts.

The price of our objects of love.
 
First off I want to compliment you are on your post detail. Probably the most complete, blow by blow detailed post of prior work I have ever seen!!!!

We need you to start running a newbie posting class here for newbies that spend half a page talking about picking up their girlfriend and how the jeep just died and want us to diagnose the problem for no info, LOL!!

The TPS sensor and wires (highest on the list) and the Map sensor and wires (low on the frequency list, but are on the list), and MAP sensor vacuum hose (very high on the list may be loose and leaking vacuum, and you should test and inspect the ballast resistor in the fuel pump wiring, and you have eliminated the O2 sensor, fuel pump....) are the most common causes of hesitation during acceleration I know of on a Renix rig that I do not see covered on your list yet. Also the vacuum line on the fuel pressure regulator may be getting fuel from a bad diaphragm in the FPR.

Also there is an EGR valve on the Renix engines that needs checking!!!!

Renix TPS sensors have two sides, one talks to the ECU, the other to the TCU, and either side can be bad, the other good, the ground can be bad on either side, and can cause your problem, so test them all!!!!!

Lastly, check the spark coil and ICM to spark coil contacts hidden under the HV spark coil, inside the ICM, Ignition Control module. I doubt it is your problem, YET! LOL.

phat87mazdarx7 said:
I've searched and searched for weeks several forums and nothing has worked so I joined here to see if anyone can give me some pointers..

I just recently bought a 88 cherokee for 400 bucks with 183k, it had a brake issue where it was locking up the drivers rear wheel(parking brake equalizer was sitting in the drum loose) so new shoes, new hardware kit, brake adjuster kit(none of it was there, lol) and new springs for the bar, and new parking brake cables. anyways I've got about 800 in parts in this thing and took it for a ride and boom, death wobble, fixed the drag link and the tie rod on it, and everything else was tight, and its better but I still had looseness on the actaual steering column shaft u joint, so I gotta fix that with a used one from the junkyard this weekend. Im assuming that should cure my death wobble. Right??

then my other issue... This car was never maintained Im assuming, so... It recieved a full tune up, Plugs(gaped at .30 or whatever it said under the hood), plug wires, cap, rotor button, di-electric grease on all the terminals, a new(used) injector... one injector wasn't firing so I pulled them all out cleaned them all wiping them with carb cleaner then took a 20oz bottle and filled it up with fuel injector cleaner drilled a hole in the cap and stuck a fuel line in it and attached it right to the injector and squeezed and gave them power(some sprayed weird but cleared up shortly) and back flushed the injectors too. and put it all together with new o-rings and vasaline.. it runs like a freaking top now, sounds great and pulls hard!!!! till you drive it, then it wants to pop in the intake and like stall no misfire I dont recall but definitely runs bad.. so I pulled the cap off the rail and pushed the bleeder valve and really low pressure.. so new pump and sending unit(since the gauge didnt work) I pulled the old one out.. its a rusty nasty mess.. and the fuel is even brown.. so cleaned up what I could feel in the sump and put it all back together.. and it runs great and drives great now, until it starts warming up. then the hesitation is back and it wont move out its own way and will barely put up a hill... I saw a few people mention the O2 sensor since other people had issues after warm up, so I unplugged it to run in open loop, took it for a drive, and ran like normal then when it warmed up, hesitation was back. so its not the O2(though I'm sure its probably never been changed like everything else on the jeep) but I'm tired of spending money and still cant really drive it.. any one have any ideas??

Its an 88 cherokee 4.0 automatic 4x4, when i got it I noticed it had the wrong radiator(it had a radiator cap) so from info from this forum and others I decided to completly trash all the old stuff and upgrade to the 92+ style so i got rid of the pressure bottle thing and replaced it with a overflow from the auto parts store new radiator cap as the old one was pushing water out the overflow(bad spring), put new heater hoses and got rid of the leaking heater valve, got a newer water outlet with the sensor since it had no sensor attached(since its supposed to be on the radiator) and universal fan hard wired was trashed for a used stock one, and everything was extended and wired up and fan works great(but it has never got hot enough to use it, runs about 200-205) it has a brand new fuel pump with the sender(previous one didnt build enough pressure and whined really loud) new pump builds the pressure(visually inspected from the bleeder on the rail) but it whines pretty loud and is annoying too :/ the exhaust was a hacked up mess, found a good used stainless looking one in the junkyard(muffler back) and its running catless right now(sounds good :D) engine wise i cant think of anything else but heres the list of everything I've put into it:

radiator cap 5.99
overflow bottle 9.99
5/8 hose 4.17
5/8 hose 4.17
3/4 hose 6.46
flush kit 3.99
idler pulley 15.99
1/4 screws 3.29
valve cover gasket 5.99
water outlet gasket 2.29
spark plug wires 22.69
spark plugs 16.44
distributor cap 12.99
dist rotor button 11.99
thermostat 7.99
brake adjuster L 9.49
brake adjuster R 8.59
hardware kit 8.09
u-joint 13.09
front pads 12.99
rear shoes 24.49
oil for rear end 11.98
engine oil filter 0
enigne oil 12.97
silicone 7.49
radiator fan 23.2
wiper arm 4.05
thermostat housing 5.63
visor clip 1
enviro charge 2.35
Brake parts cleaner 7.41
Lugnuts ebay 15
parking brake cables 21.98
parking brake springs 1.69
overflow hose 4.95
pvc valve elbow 2.59
pvc grommet 3.29
nuts for bumper 3.29
injector seals 4.49
blower motor 28.99
blower motor resistor 23.99
muffler 14.01
antenna 3.28
bumper brackets 13.64
bat tire good aluminum rim 20.33
dome light cover 1.35
seat belt connector 4.28
exhaust pipe 20.97
hanger 2.99
speakers 25.76
tires 40+10 gas 50
tires mount+balance 52
fuel pump 104.09
drag link 24.29
tie rod end 15.59
oil 12.97
gas treatment 1.57
fuel injector cleaner 1.88
dome light 3.97
foot light 3.97
radio connector 9.72
driver wiper 4.97
rear wiper 4.97

Subtotal 794.11
Tax 55.5877
Total 849.6977


does anyone have any ideas what this hesitation could be or what and how could I check stuff, does the knock crank and cam sensor work like the O2?? unplugg it and it just bypasses that system but will still run. I just need to get this jeep on the road.
Click to expand...
 
Digger87xj said:
I didn't see a fuel filter on that list.
Click to expand...

Good suggestion since he said there was so much rust-junk in the tank. He might be getting just enough flow at idle, and then be loosing flow and pressure at high demand during acceleration.
 
it has a brand new fuel pump with the sender(previous one didn't build enough pressure and whined really loud) new pump builds the pressure(visually inspected from the bleeder on the rail) but it whines pretty loud and is annoying too
Click to expand...

What brand fuel pump did you get?

a new(used) injector.
Click to expand...

So you replaced one injector? What is the flow rate on that injector, brand, part number....?
 
Re: Re: 88 cherokee 4.0L 4x4 hesitation, please help

Ecomike said:
Good suggestion since he said there was so much rust-junk in the tank. He might be getting just enough flow at idle, and then be loosing flow and pressure at high demand during acceleration.
Click to expand...

Ed Zachary!
 
You must log in or register to reply here.

Similar threads

WGxj
1997 XJ 4.0L AW4 Long Crank Problem
Replies
5
Views
98
Tim_MN
Tim_MN
O
Rear Brake Noise Question and Hepl Please
Replies
5
Views
383
asymptonic
A
J
2001 4.0L issues
Replies
15
Views
282
Saudade
Saudade
X
Quick diagnosis please, sudden engine roughness
Replies
7
Views
1K
XJ Monkey
X
Ecomike
87 Renix XJ No fuel, No brake lights, cranks fine
2
Replies
27
Views
882
Anak
Anak
Back
Top