4.0 Cherokee Cuts Off!?

TapouT

Well-Known Member
Joined
Oct 5, 2008
Location
Hickory nc
My Jeep has acted up on me since I've had it. It's not bad but it does get annoying. About 10 seconds after driving the Jeep when I come to a stop it stumbles like it wants to shut off but if I put it in neutral and rev it up a little bit it stops...But then when I go to take off it stumbles and I have to give it more gas to get it to go. If I don't rev it up in time and it does shut off I stop and crank it again and it idles really high for about 3-5 seconds then idles back down and does fine for a little bit but then the next stop or two that I come to it starts doing it again. What could be causing this? It doesn't stumble when driving, only when coming to a stop and/or taking off..
 
What these guys are saying could be true, but before I spent money on them, I would check the basics. You may have already done this, but check the belt and pulleys to make sure that everything is good. Believe it or not, i had a friend with a similar situation on a late 80's model cherokee and I drove 70 miles to help him troubleshoot and fix it when all that was wrong was that the serpentine belt was old and loose and needed to replaced and tightened. just saying, check that out before you go tinkering with your sensors. But if it isn't the belt, it is most likely the neutral safety switch. if that doesn't work, it's probably the crank pos sensor.
 
throttle position sensor (tps)

try cleaning your throttle body also, make sure the butterfly is operating in its full range, and not sticking or anything

hope this helps, and keep us informed
 
I haven't really had a chance to mess with it but I got to drive it some more...It seems like the longer you drive it the more it wants to cut out when I'm coming to a stop. I have to put it in neutral and start revving it up before I stop and usually when I do that it's like the idle gets stuck at whatever rpm I revved it to and it'll stay that way for almost 8-10 seconds. :wtf:
 
We have seen many different problems with the 4.oh's. From like the others said, cps, tps, iac motors being carboned up, all the way to faulty ECUs. Start simple. And work your way up. Is the check engine light on? sometimes the ignition coil will begin to fail and throw a code, but generally the vehicle will die at stops, not just stumble... GL!
 
TapouT said:
I have to put it in neutral and start revving it up before I stop and usually when I do that it's like the idle gets stuck at whatever rpm I revved it to and it'll stay that way for almost 8-10 seconds. :wtf:
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That sounds like a sticking or carboned up IAC motor... Its on the back side of you T/B. Try cleaning it with Throttle body cleaner, AS WELL AS THE THROTTLE BODY ITSELF, by spraying it through the T/B side opening. Open the throttle plate and there should be an opening to the IAC motor... If you remove the IAC, chances are you'll need another gasket/o-ring so try cleaning it first. When you do that though, remember it will be had to start at first because of all the t/b cleaner that more than likely made its way into the intake...

Here is a diagram to help you out
ai166.photobucket.com_albums_u88_sleeperwagon1_40throttlebody.gif
 
tahoeon44's said:
That sounds like a sticking or carboned up IAC motor... Its on the back side of you T/B. Try cleaning it with Throttle body cleaner, AS WELL AS THE THROTTLE BODY ITSELF, by spraying it through the T/B side opening. Open the throttle plate and there should be an opening to the IAC motor... If you remove the IAC, chances are you'll need another gasket/o-ring so try cleaning it first. When you do that though, remember it will be had to start at first because of all the t/b cleaner that more than likely made its way into the intake...
Here is a diagram to help you out
ai166.photobucket.com_albums_u88_sleeperwagon1_40throttlebody.gif
Click to expand...

One of the first things I did was clean the IAC motor and TB. I ended up pulling the IAC off though. I didn't know you could spray through the throttle body to the opening of the IAC. It won't hurt anything opening the throttle plate wide open so I can clean down in there while the Jeep is off will it?
 
I don't have much to add other than the fact that mine does this too. Mine seems to be related to getting warm. It runs fine when I'm moving but it doesn't like to crawl at near idle speeds for more than 10 minutes or so.

I've replaced the CPS several times but it hasn't been a long term fix.
 
tahoeon44's said:
We have seen many different problems with the 4.oh's. From like the others said, cps, tps, iac motors being carboned up, all the way to faulty ECUs. Start simple. And work your way up. Is the check engine light on? sometimes the ignition coil will begin to fail and throw a code, but generally the vehicle will die at stops, not just stumble... GL!
Click to expand...

The check engine light isn't on and sometimes it will shut off if I don't put it in neutral and rev it in time. When it does die it starts idling real low and I think the honeycomb in my catalytic converter is busted because it rattles pretty bad and when it starts rattling when coming to a stop that's my cue to put it in neutral and rev it up a little to keep it running.
 
To answer your first question. Yes it's ok to spray down inside the t/b...

And about the rattling Cat. Sounds to me like someone said above that the converter is falling apart inside. This may also be your problem. A plugged cat. can cause all kinds of issues...

Again GL and lmk if you have any more questions!
 
TapouT said:
The check engine light isn't on and sometimes it will shut off if I don't put it in neutral and rev it in time. When it does die it starts idling real low and I think the honeycomb in my catalytic converter is busted because it rattles pretty bad and when it starts rattling when coming to a stop that's my cue to put it in neutral and rev it up a little to keep it running.
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I dont know may be on a wild ass goose chase here....but if it only cuts off when you here the rattle and the rpms are dragging low at idle, I have to wonder if the rattle you are hearing isnt coming from your torque converter going out, and when at idle it is bogging the motor down
 
SkyHiK5 said:
I dont know may be on a wild ass goose chase here....but if it only cuts off when you here the rattle and the rpms are dragging low at idle, I have to wonder if the rattle you are hearing isnt coming from your torque converter going out, and when at idle it is bogging the motor down
Click to expand...

It's not the torque converter. I've gotten up under the Jeep and listened to it and it's coming from the catalytic converter. You can get up under the Jeep and tap the cat with something when it's not running and hear something rattling in there. I might end up taking the cat off and running a straight pipe into a muffler and turn-down. I just don't want it to be too obnoxiously loud.
 
Punch the cat out and put it back on you will need it IF you have it inspected. (yea, it may not work but the inspection law says you must have one)
 
sounds like what someone said earlier, clean out the throttle body and check the idle air control valve/motor.
 
OK XJ 4.0L EFI history lesson the 87-90 have the Renix fuel system which do some very strange things, the check engine light very rarely ever come on and if there is a code it is erased as soon as the key is turned off. The 91-01's have various Chrysler fuel systems
Since you have a Renix system most often the failure is the TPS is out of adjustment there is a way to adjust it without a scan tool but I have not done that in years on a scan tool the TPS % should read @ 12-13% engine off.

The next thing is the EGR system can stick open and cause a low idle and engine stalling.
 
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