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Hey guys, I have a issue going on with my 2000 Grand Cherokee 4.7 Limited, after it warms up it starts to stumble and will stall. it cranks right back up but will repeat the same thing. It is not throwing a CHECK ENGINE light and i have scanned it anyway but got no codes. I had a 97 4.0 that did the same and would back fire and found out it was the ecu. It only happens after the jeep warms up…….20-30 min of driving…. please help!!!!!!! 🙁 🙁 🙁 🙁 🙁 🙁 🙁 🙁 🙁
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sounds almost like a temperature related issue, does it smell like its running rich when it stalls out?
No, no rich smell at all. i took it to 3 shops and they checked the cats to see if they were plugged and nothing, they also changed the o2 sensors and did a tune up….still nothing.
I’d start checking for vacuum leaks, honestly. If there’s a small crack, it might be small enough to remain sealed when cold. But things expand when warm, and a vacuum leak at the wrong place at the wrong time can easily cause stumbling and stalling like you say.
Here’s a link to Eric’s ‘Finding a Vacuum leak’ video: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CB4Q3ywwAGoVChMIxuKIm6HRyAIVhI4NCh34nADd&url=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D9CPqbaSgcok&usg=AFQjCNFUyl9bvl-_fhGP7hrPW43aPj_XgQ&sig2=r3WwgZWvUZGC1NLpwqTbxw&bvm=bv.105454873,d.eXY
Sorry about that, that’s the one I found on the YouTube, but it’ll do. 🙂
Good luck!
-Hinoki
Does it only stall at idle or will it still stall if you give it a little throttle when it starts to stumble?
it will stall and stumble at idle (at a red light) and sometimes if i give it gas it goes away and sometimes it will stumble on acceleration.
smoke test was done and no leaks were found. cats where changed along with all 4 02 sensors and it still does it.
If it hesitates while accelerating it wouldn’t hurt to check the TPS readings while driving with a scan tool. I’ve had a TPS sensor go bad on a 4.0 WJ and it didn’t throw a check engine light until it got really bad. I watched the live data while my brother drove and sure enough the TPS reading would drop out to 0% occasionally.
Ok guys the problem fixed itself for awhile then came back. Well I was adding the Lucas Fuel injector cleaner and it seemed to go away. But again it is sparatic, while driving mostly at idle the engine will stumble and the Rpms will drop it will almost die then pick back up. While driving it will lose power until I floor it. 99% of the Times it won’t stall but if it does it will start right back up. I have dumped some B12 fuel system cleaner in it in the past 2 weeks but no change. I got one of those Bluetooth elms to see live data but don’t know what to look for. The plugs were just changed, so was the crankshaft sensor and the fuel filter. I also cleaned the throttle body. Btw it is not throwing any codes and does not happen all the time.
Update:
Checked TIPSand cleaned Ac and throttle body and it still is doing it. I also changed the plugs and fuel filter and pulled each coil over plug and checked resistance. .. Found no issues. So I ordered a Idle air control sensor yesterday to see if the helps.
like i said in another post check the engine computer i had similar issues and no matter what was done the issue remained it would run a Little sluggish at times it would stumble and stall while stopping or at a light would always start back up did not matter weather it was hot or cold there was never a check engine light and the jeep would pass emissions as well turned out a i had a faulty engine computer which was common for a number of years in older jeep grand Cherokees i had read people where changing tpms sensors spark plugs adding fuel cleaners changing crank sensors iac in order to fix this issue only to find i did not fix the problem then i ran across a video about the computers being faulty went and checked mine that was the problem right off put in a new ecm and no more issues do not get a junk yard computer you want a new or re manufactured computer also if its not the computer check the wiring going to the computer the computer will cost around 500 to buy from autozone so be sure thats the issue go pop the hood and with it running jiggle the 3 wire connectors to the computer you may have to remove the coolant bottle to do so if the engine stumbles or you hear a change in the way it runs each time you jiggle it then its either your computer or a wiring issue usually its the computer the joints or pins in the computer like to crack brake etc and when it does it causes these issues most of the time its the computer but not always if i had not found that video i would have spent 1,000s in parts i did not even need but almost every jeep ive seen from this time period has suffered at some point from faulty computer also the cats like to go bad i had his issue on 2 different jeeps other then that there great i love mine i have been told to trade mine in but i wont let it go im going to drive it till the motor or tranny goes in a big way good luck on your issue.
I will check it in the morning. I did have to replace the cats once it has cali emissions and the 02 sensors several times.
im not sure if the cats are still a issue but they seem to like to go first time i experienced it i thought it was my tranny i had gone for a long drive pulled off at a store stopped maybe 20 min then i went back got back on the road headed for home 30 miles down the road i stopped at a light then i noticed it wasn’t accelerating right and ti was then shifting about 2,000 rpm so i though i was having a tranny issue it was late about 10 pm so nothing i could do no warning lights i pulled over checked my tranny fluid it was fine so i continued home i no change in performance i noticed it had begum to guzzle fuel more so then normal got home parked it over night went back cranked it up ran normally till everything heated up i thought i would drive it to the shop 10 miles away wrong i was to so got about 5 mils down the road going up a hill it lost all power would no longer go over 5 mph did not check gauges i kept driving to the top so i could coast down and pull over at a near buy gas station still had the ac basting it was blowing col i got to the top noticed my temp gauge was up the the quart mark past 210 im like crap i coasted it down pulled over poped my hood it was spewing coolant out the coolant overflow tube turned it off called for help my convert had broke apart and plugged up. i never got a check engine light. i didnt even know till it was too late before hand the exhaust sounded normal mpg was normal and it ran fine i never had any warning till i was 100 miles away from home.
Checked the ecu and it did not do anything idled perfect. So I have one of those ELM 327 doggles so I checked the live data using the torque pro app and at idle my tps reads 11.4% I called a friend of mines who has a jeep same year and model but his has the 4.0 and had him come over and I compared his live data and his at idle was 19.2%. But both of our techs were reading the same revs around 640ish so could it be the tps? I know mine is the 4.7 and his a 4.0 but that is a big gap.
how does your fuel trims and o2’s look???
want Im wundering if your running rich or lean at times… you will have to run it for a little bit and see how it goes
clean the spring and make sure it snaps back quickly and easylya bad tps can cause a hesitation and stall from what ive heard i however have never had to change my tps sensor you cold check with a volt meter for dead spots if it has any dead spots its bad it can also cause the transmission to act funky in some vehicles but ive never had a issue with tps mine is still factory so im sure its due to go anytime now i also have the 4.0 instead of the v8. if i had a scan tool i would check live data and see what mine was running at my jeep also idles around 640ish rpm.
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