2002 Jeep Grand Cherokee Laredo – Stalls at Slow Speeds
Reader Question: I have a 2002 Jeep Grand Cherokee Laredo v-6. When I am idling at a light, my jeep has shut off about seven times. It starts right back up though.
When I am idling and sometimes while driving my car will rev up and the RPMs go up and then back down to normal. It feels like the jeep is trying to shut off but then the RPMs go way up to stop it from shutting off.
I went and put it on a computer at a local auto zone and the problem that came up was the throttle sensor. I also went and had a fuel injection cleaning at my local oil change place and when they were doing it, a bunch of white smoke came out of the tail pipe. I was told this was good that it meant the fuel injectors were very dirty.
I was hoping this would be the answer to my problem. However, unfortunately not, the next day it started acting up again.
My question is – do you think the bad throttle sensor could be causing the car to shut off like this? The part is US$75 and then I need to pay someone to install it so I am wondering if I should spend the money or it was suggested by a couple of people that I possibly could use a tune up, which I know is good to do anyways but I am trying to fix the problem at hand.
In addition, the check engine light has been on for a long time but when I read the manual initially, it said that this light came on and it meant I had put some bad gas in.
Please help me with any information you think I need!
Thanks so much,
Lauren
Hey Lauren,
If the check engine light is on, I would definitely spend US$75-100 to have your computer codes read by a real mechanic; not at Auto Zone…they are great for buying parts but not for diagnosing computer related problems.
You could very well have a TPS – Throttle Position Sensor problem, but this problem could be caused by many other issues as well, so before I guessed at a US$75 part I think I would have someone look into it further.
A dirty throttle body and idle speed motor can cause a common idle surging and dying at low speed complaint, which is part of the fuel injection system. Your local oil change guys may or may not have cleaned the throttle body and idle speed motor when they did the “fuel injector cleaning”.
Although a dirty throttle body and idle motor will cause dying and idle surge complaints like you mentioned it will usually not cause the check engine light to come on.
The check engine light is continually coming on due to a consistent problem your onboard computer is seeing when it performs its self-tests. One of the man emissions control sensors is usually the culprit of a yellow check engine light being on. A drop in fuel mileage and engine performance can sometimes accompany a yellow check engine light being on.
Needing a tune up could cause poor engine performance, but you did not mention anything about the engine running bad OFF idle so I do not think you need to get a tune up to correct this problem and I really doubt you have a “bad gas” problem.
Here is more about the throttle body and idle motor on my blog:
Blessings,
Austin Davis
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I have a 2002 laredo jeep and it has about 97000 miles on it. it seems as if “nothing” is wrong with it however similar to some stories i have seen online. when i crank the jeep, it revs high 2.5-3K sometimes. and if you dont let it sit and warm up it slams into reverse. i live in FL and its not like the truck is freezing before i leave. sometimes it takes over 10 minutes to get the idle back down.
with that being said, it drives great and doesnt seem like it slips and i have been told that there is nothing wrong that any car will do that when its cold. i have had my share and i have NEVER had a tranny slam so hard into reverse. and if im just sitting there, it revs up and down.
if im getting on the interstate, it goes good until about 50mph where it goes into its final gear where there is no “down shift” to make it get up and go. there is no power what so ever at 50-60mph which im being told at the dealership (not jeep) that there isnt anything wrong.
everyone says the same thing, nothing is wrong. i wanted to move to TX from FL but im scared that it wont make the drive with whatever is happening. i dont even know where to start.
any ideas? do you think it could be this throddle sensor? i know im not crazy and there arent any lights on saying there is an issue but i know that there is something and no one can tell me what it is.
help??
We had a customer in my shop years back with the same vehicle and same problem….and they seemed to think things were fine so we did not “repair” anything but I was shocked that it would idle so high for a few seconds, but they were not concerned.
I would visit the Jeep dealer again and talk to another service manager. I think you DO have a problem…maybe a throttle position sensor, maybe a dirty throttle body, maybe a problem with the fuel pump…I am not sure but I agree with you, something is not right. If you dont have any power at freeway speeds it would lead me to believe there could be a lack of fuel pump pressure.
Sorry I cant really help you more. I hope you can find a mechanic who will spend a little time investigating this for you….and let us know what they come up with.