Plhammond

Greetings all. Have 2000 grand Cherokee 4.0 will not stay running starts right up runs for about 20 seconds an then shuts down it has 50 psi fuel pressure I do know it will stay running because it was driven to my home after I bought it but started this after we turned it off and let it sit for a while.need some help to start looking in right area.thank you PETE

Cleman Simpson

A friend of mine had the same problem with a car he set up for a couple of years. It was a buick, not a jeep, What we found was that the mass air flow sensor had kinda corroded up but not so bad we had to replace it. We removed it from the car and sprayed it down with a cleaner made just for that. I think we got it from auto zone. The car ran fine after that. Don't know if this is your problem but maybe something to look at. does the jeep throw any codes? Could be a number of things, maybe cps going out, computer problem, security system...

Edit to add, if you pull the air flow sensor be careful to not touch the part that does the sensing with your fingers, it will ruin it..

Plhammond

[s][b]Thanks for your reply cleman I have discovered that it is the key security system (new to jeeps) but have tried mas air f
low spray on my subaru that cured problem. Thanks again.Pete

dave1123

Jeeps don't use a mass airflow sensor. They use a Manifold Air Pressure (MAP) sensor combined with an intake air temp sensor. (IAT)

Your problem is with the SKIM (Security Key Identification Module) and the chipped keys. There should be 2 factory supplied keys, a grey one and a brown one. Aftermarket keys are all black. All the keys have an RF chip in them that the SKIM reads and if the code it gets back is programmed into it, will allow you to drive the jeep. If it doesn't recognize the code, it will shut off quickly.

What color is the plastic on the key you are using? If you have 2, try the other one.

Plhammond

Dave 1123 hayDave the keys look to be a light brown/gray color.They both say jeep on them not that that means anything Pete

Cleman Simpson

Glad you found the problem, and I learned something new. I'm not new to jeeps but I am new to working on them. I owned a wrangler before this GC but I bought it new and it never gave me any trouble. I bought this GCL last September to hunt with and the engine has rtun pretty good in in except for a couple of hiccups. I have been working all my life on hot rods I built and personal 4x4 trucks etc, and am a high school and college trained mechanic but that training is pretty old, LOL, as am I. Most of the post I make are based on general engine theory diagnostics to help narrow down the problem for inexperienced mechanics until a Grand Cherokee expert like Dave can get to his keyboard.

dave1123

It sounds like you have both factory keys. When you insert a key and turn it on, does the light with the key in a circle turn off after the rest of the warning lights do? If it doesn't, there may be a problem with the SKIM module itself. Funny it should happen the day you brought it home.

Plhammond

Dave when I bought this rig it had tranny problems among others it's kind of a progect truck I got it for real cheap.But where I plan on going with it it has to be reliable walking out of 100 miles of desert won't be good. So with that said. Yes the dash light goes out when the lights clear. Dave is there a sanitary way to disconnect this feature ? Bye the way this rig has been in my garage on stands for two weeks maybe three with the battery out. And tranny tore down door regulator out etc. I'm trying to go through it front to back and it's my first jeep so I'm still on the learning curve with it however I'm retired so it gives me something to do. And thank you for your help.Pete

dave1123

AH.....so the PCM lost all it's memory! That explains a lot. Unfortunately at this point I'm not sure how to fix it, but I'll do some research.

If you are so inclined, you can download a Full Service Manual from pacificcoastmanuals.com for $7.99+tax. It's a reprint of the factory FSM used by the dealer techs and is year specific so you don't have to search thru reams of data to find what your jeep has for your year. It's 93mbs of compressed pdf files on everything in your jeep. Lots of circuit diagrams, component locations, removal procedures, and troubleshooting problems. Even explanations or how the systems function. It is the BEST reference I've ever seen! It even covers diesel jeeps that we couldn't buy in the states.

This is where I get most of my data to tell you guys what's what!

Plhammond

Thanks Dave I will give that a shot. Pete

dave1123

Near as I can tell, it might not be the SKIM, but the security system itself, is in the immobilizer part of the alarm system. It's probably going to take a DRBIII scan tool to work it out. Sorry.

Reading back thru your posts, I see you have a window regulator out. If it's a front door, you have the door module out as well. The RKE transceiver is on the passenger's door panel so that might have something to do with it not running, IDK. I'm just grasping at straws here.

Cleman Simpson

I got a strange one for you Dave. A couple of weeks ago my key ring broke without me knowing it and I lost the only key I had to my GC. By some strange divine coincidence the previous day I had found an old spare key to a 2007 Ram that I traded in several years ago and of course I had to try it in the jeep. to my amazement it not only cranked the engine but it runs and drives perfectly, but it will not unlock the doors. Can the jeep dealer make me a new key from the vin numbers?