zonexero

Hoping someone can point us in right direction. We have a 2000 Jeep Grand Cherokee, it has about 152k miles on it. About three weeks ago it developed an interesting problem I cannot figure out. After the vehicle has been sitting for more then 3hours+, you go to start it and it starts fine, you can hear the fuel pump priming, when starting it, however the engine runs a little rough, like it's slight stuttering for fuel. When you get out on the road and get up to about 30-35mph, it starts acting like it is not getting fuel, and starts to lose power, if you try to accelerate, it seems like it loses more power. After driving about 3-6miles, the problem goes away, and it runs fine after that.
We ran two different handheld computers on it, both show everything ok 100% across the board. We have replaced the fuel filter, and checked the vacuum line, they also are ok.
Any ideas here? It seems like a fuel problem, but the odd thing is it only does it when the truck is cold (as above sitting for more then a few hours), after that it is fine. Be grateful for any pointers. Hoping this is just a sensor or something, we don't have a lot of money to spend on it, and our dealer here wants 150 bucks just to look at it. Thanks. If I posted in wrong forum, please let me know where this should be.

Creature85

Sounds like it could be your CPS. Here's a nice write up on how to test it.

https://www.cherokeeforum.com/f51/testing-cps-5563/

Bustedback

Check the fuel pressure. A cold engine requires more fuel and your pump may not be keeping up with the demand. Original pump?

zonexero

Bustedback- It may be the original, we don't know since it was bought used a few years ago, something to look into, anyway to know for sure?

Creature85- It looks like an easy test, I will give that a try. Thanks guys.

dave1123

You can put a pressure guage on the fuel rail. You can probably rent one from Autozone or other store. It just screws onto the schrader valve on the fuel rail. Then you can check pressure when it's giving you the problem. The pressure should be 44 to 54 psi with engine running.