Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Jeep Grand Cherokee Start Stall Idle Problems



  • I have the exact same problem as Swelms. I own a 1998 Jeep Grand Cherokee Laredo and if I have been driving for a long time, the power just dies. The speedometer goes down and the rpm drops from 3000 to 1000. If I give more gas, than the car brakes.
    I usually let go of the gaspedal for a few seconds and then I can drive again, but this only resolves the problem for a little bit and eventually I need to give my car a rest for about 20 to 30 minutes and then it is fine again.

    I asked a few mechanics and even in a Jeep garage, nobody had ever heard of this problem. So I really hope somebody can give me an idea what the problem is and how to fix it?

    Thank you soooo much!!!
  • ralkaralka Posts: 72
    I have an 02 grand cherokee (v8) when driving home i thought i felt a misfire but got home without a continuing problem. when i went to start it the next day it cranked but wouldn't start. the codes that i found ( 7 of them) were po455 ,po171. po174,po442.po158,po161, and po0300 i can relate there discriptions if needed but they are basically evap leak large , o2 sensor 2 on bank 2 heater and high voltage, random misfire and bank 1 and 2 lean. the light of course had come on but it ran great until i felt the misfire. any help on where to start would be greatly appreciated
  • danny80danny80 Posts: 7
    I would recommend to check up the heated wire sensor in the air intake. The wire sensor is very often dirty by the air deposits - grease dust etc. It makes a signal distortion and possible control problems.
    The cleaning is very simple, only be careful not to damage the wire.
  • danny80danny80 Posts: 7
    by my experience it runs as follows:
    - the bank 2 O2 upstream sensor is bad - trouble codes P0158 - P0174. It costs a few bucks only
    - the unevitable misfires follow - P0300
    - after that goes too much unburned fuel to the charcoal cannister, that cannot to process it - code P0442.
    Have the upstream O2 sensor checked and replaced, then deleted the DTCs.
    I hope it helps
  • ralkaralka Posts: 72
    thanks for the insight, i will replace the o2 sensor first and see where that leads. i will let you know if that works
    thanks again for the help
  • danny80danny80 Posts: 7
    I wonder if it comes right.
    I may only have been wrong in one thing: the EVAP cannister absorbes fuel vapours from the tank primarily. But is connected to the PCV valve, there could be a little bit unburned fuel which makes problem for the emission control system.
    I think faulty O2 sensor is essential.
  • jhart4jhart4 Posts: 1
    Here's my suggestion for this problem. I am posting this solution in various places because there are many forums and this problem seems to be widespread.
    About a year ago, my 97 GC started with the stalling problem. I have replaced everything that everyone talks about ...It is a complete shutdown of ignition....Code readers say that it is the ignition coil, or ignition coil signal. It is also very random....and not necessarily heat related. Sometimes, the vehicle won't start after sitting all night....sometimes it will stall when backing out of the driveway....sometimes after 10 minutes of driving....sometimes not at all for a trip to the store, but then stall several times coming home from the store. One thing is for sure….it gets worse and worse as time goes on.
    Sometimes, it helps to disconnect the battery....sometimes, it doesn't. There are times when it refuses to restart, and then unplugging and replugging various sensors helps. Sometimes, it helps to reseat the PCM connectors....and then sometimes it doesn't.
    Well....I've been through all the replacement stuff...I've traversed the awful sensation of the car stopping suddenly while I'm in the center lane during rush hour....I've experienced the horror of stalling in the middle of an intersection, and the frustration of not getting to work on time.
    Oh baby...I know this problem...and I am a long-time veteran of electronic circuitry. I am a component-level troubleshooter, and I was not about to allow this problem to win the day.

    Unfortunately...this problem is allusive in it's randomness....and also by the pesky disappearance when you replace a sensor....then it rears its ugly head a few days later. So......after $500-$1000 worth of component are left with the same problem and a box of used parts that probably were never bad to begin with.

    So....On to the solution. Now, one person on another forum suggests shortening the length of the PCM cover screws a bit. I’m not convinced that this does anything…but it seemed to work for him.

    Nevertheless....I was willing to shorten up those screws, simply because it doesn't hurt to give it a try. There's no doubt that the problem rests in the PCM Connector configuration. Whether it is dirt, corrosion, or poor intimate contact....the problem is there.

    I've noted that several people claim success using zip ties on the connectors, and while this may work, I am uncomfortable with the use of zip ties because they put stress on connectors in weird directions....the problem may return over time.

    I was convinced that the solution rests in ensuring a zero-vibration environment at the connector. But the connectors needed to be seated firmly and perfectly perpendicular to the surface of the PCM.

    The screws? well, they might play a part in all this, but I could see nothing down in the screw holes that would suggest a short circuit with a circuit board is just an empty hole. The screws could be corroded, and not making good contact...but if you remove the screws completely, the symptoms don't change. Sooo I'm skeptical.

    So, I ran into a forum post elsewhere that describes this same problem, and the creation of a connector bracket. This sounded perfect. So I made one. It cost me $6.43 for the took 15 minutes to make the bracket....and 45 minutes to install.....and my stalling problem is gone.

    Very simple. Go to Home the following junk:
    1 - 36" Steel Bar 1" wide X 1/8" thick
    2 Bolts 4" long X 1/4
    2 Wingnuts (1/4")">

    From the steel bar, using a hacksaw, cut off 2 lengths of bar 9" long each.
    Drill holes large enough for the bolts on both ends of the bars
    One bar goes behind the PCM
    One bar goes on top of the connectors
    Use the wingnuts to tighten the connectors firmly into place.

    Remove your battery cables and short them together (use a wrench or screwdriver)
    Remove the coolant overflow tank hose...set aside (1 minute)
    Remove three coolant overflow tank mounting screws (5 minutes)
    Remove coolant overflow tank (1 minute)
    Remove PCM Connectors from PCM (1 minute)
    Remove 3 PCM Mounting bolts (5 minutes)
    Remove PCM (30 seconds)
    Remove screws from front plate of PCM and grind them shorter or replace them with shorter screws (just in case)(5 minutes)
    Place one bar on backside of PCM...Place other bar on front...then wingnut them in place from the front(this is just to get the bracket in place because you can't put the bolts on while the PCM is still mounted on the firewall) (2 minutes)
    Now Mount the PCM back onto the firewall (5 minutes)
    Loosen the wingnuts out to the end of the bolts....Install the connectors....tighten down the wingnuts with great zeal, but not so much as to distort the bar very much. (there will be some bow in the bar...but don't sweat it)(5 minutes)
    Now reinstall your Overflow coolant tank (5 minutes)
    Reconnect your battery (2 minutes)
    Start Car and Drive away.
    Stop Car..get out....close hood...Now drive away
  • ralkaralka Posts: 72
    i had a chance to look at the jeep (02 jgc 4.7) today, and found that there is no fuel getting to the throttle body. i than shot some 2
    +2 down and it did run briefly, i than pulled the fuel filter/regulator above the rear differential and pulled one of the lines going to the tank and cycled the ignition to see if any fuel exited the line (none). i am thinking fuel pump but i do hear what sounds like the pump starting when the key is turned. does anyone know if the pump can be running if it is bad and is there anything else that will stop fuel pressure to the engine?
  • wam22wam22 Posts: 1
    Hope the oil sending unit was your problem. I had the same problem but it turned out to be much more extensive. Not trying to scare you. I had about 210K on the original engine. Apparently the engine bearings get out of shape and when the engine warms up the oil pressure drops. I replaced the oil pump and tried a more viscous oil which helped a little. Drove the engine for another year or so until I finally ended up with a hole in a piston from lack of lubrication. I replaced the engine myself but it was still $2k. Good luck and I hope it's minor.
  • pjd1280pjd1280 Posts: 2
    edited August 2012
    I can be driving and not only does it stall but it loses ALL power! Also once I get somewhere and shut it off most of the time it won't start again untill it cools off. I have changed the plugs, and the coil, checked the water and the trans oil. This started about 6 mos aga and is getting worse! Help this to lady that service tech poor to fix it please? :(
  • wdjrwdjr Posts: 1
    edited August 2012
    I have dealt with same problems with my 97 cherokee. replaced everything with no luck. Did the screw thing, and every other thing that was suggested. I finally stumbled across this video on youtube. I did just what the guy said and that was the end of the stalling/not starting problems. Just thought I would drop it on you. The video is labeled as - 96 Grand Cherokee PCM Repair. good luck PS - if you don't see any breaks in the solder (as I didn't either) go ahead and do like he shows. They can be too small to see.
  • danny80danny80 Posts: 7
    I have experience with the 6cyl. There is a testing valve on the fuel rail nearby throttle body. I think the 4.7 has a similar one.
    You can easily test the fuel pressure - after unscrewing the cap you press the center of the valve by fingernail or tool. If fuel sprinks, there is pressure and the pump is O.K. You can also connect a pressure tester to check the pressure more exactly. If no fuel is sprinking (or very weakly), the pump is not O.K., even if you can hear a pumping sound.
  • My Jeep has 230,000 km on it. Bought it 2 months ago.
    Sometimes when I come to a complete stop (usually right after I start the car), the trottle is not responding and the engine sounds like there is no ignition. Sometimes just giving veeery little throttle gets the car going. Once the car is running again there is no problem anymore. When it does stall, putting the transmission in N, the engine will respond normal to throttle input and putting the transmission in D while the RPM is little higher than idle (600RPM) the stalling goes away. The engine has never died nor does it happen when the car is coasting.
    I read somewher that it could be the Flywheel sensor.
    Just yesterday I had all spark plugs changed, no change.
    Any thoughts?
  • ralkaralka Posts: 72
    well replaced the fuel pump yesterday, it was still able to run but couldnt pump enough pressure up to the rali.

    thanks for the help
  • pjd1280pjd1280 Posts: 2
    replaced coil, plugs . and now vaccum hose. will now check fuel pressure and that pc? thing. I will try anything I can and I will watch that utube video, as I am desperate. this is my oly car and I am stuck close to home un till I fix it. pjd
  • We had the same problem just got it fixed was the ECU module and the Fuel Puump
  • I built the steel bar tightener today and tried it out as my 97 GC has been stalling the last week. Didn't seem to help as the car wouldn't start at all after putting it in. I didn't shorten the screws, but may try that tomorrow. It just seems the only common denominator among all these "fixes" is wiggling wires just right and being lucky.

    In any case, this is pretty ridiculous that this is so common an issue without a word from Chrysler. I'm amazed that no one has died yet as their Jeep stalls out in the middle of the highway or going up some muddy hill.

    I'll share whatever miracle fix I manage to come up with, if that ever happens.
  • alby3alby3 Posts: 46
    if it is stalling at random it is your computer,,,, i got a rebuilt one off ebay and gave them my year make and model, vin nbbr and mileage. like $200 . installed it in about 35 min..... and it worked great for about 2 years..... then i went thru 5 (yes ... 5) more at the dealer ($1600 for computer , skim and instrument cluster)because of my skim light coming on and you cannot get new computers (ecu) only rebuilt..... but they did not charge me for the other 4 except for the tow charge in... that is when i sold it.... loved the jeep but need something i could depend on

    good luck
  • i have a 2000 jgc and mine would do the same thing only in any temp the key light would come on in top right corner of instrument cluster i had to get my key calibrated or something like that my key has a chip in it and the car wouldnt recognize it and would not start for minutes to hours
  • Thanks for the advice. Today I swapped the Oxygen Sensors (I'd been getting occasional Check Engine warnings about them periodically over the last year, but it would go away every time after a few miles) but it didn't make a difference. 5 miles into my test drive, it stalled out, then again on the way back.

    I've checked and secured all the grounds, built the metal bracket to hold and support the plug banks even though wiggling them made no difference, and now replaced the two known problem sensors with no luck. I guess I'm really at the point where I have to swap the PCM or break it open and see what's inside I might be able to clean up or repair.

    I'm really surprised that there's so much activity and folk remedies for this issue, but apparently no word from Chrysler over the years.
Sign In or Register to comment.