Hey I don't normally post in here but I'm hoping to exploit your expertise to diagnose a problem with my 2000 Cherokee Sport 4.0. Feel free to ignore me if you need to.

About a week or two ago while cruising uphill on the highway at about 55 mph, my Jeep bucked pretty hard and the Check Gauges light came on for about 2 seconds. It kinda felt like I hit something so I'm guessing it was some kind of misfire?

A few days later I was cruising down a hill and I think my rpms dropped for a little bit, just felt kinda funky but not really hugely noticeable.

Fast forward to today, I drove it quite a bit went out to dinner and then got back into the car, started it and was idling in the parking lot and it just died... no warning or rough idle or anything, just died. Started back up fine but on the ~50 minute drive back home it did the hard bucking misfire thing 3 or 4 times, so something is clearly getting worse.

Changed the plugs just a few months ago, I'm kinda thinking fuel pump/filter or ignition coil rails. Any ideas on where I should start? Any help would be much appreciated.

 

Fuel filter is very inexpensive. If you've never changed it since you've owned the jeep, start there. Swap it out for a new one and if it's still doing it, remove your injectors and clean them. This can be done by "hotwiring" them to a 9-volt battery to open up the injectors and then clean them with a carb/choke cleaner or fuel injector cleaner (in other words, pour the solvent into a pan and soak them.... not just run it through your tank). There are several videos on youtube on how to use the 9-volt method to open up the fuel injectors and clean them.

Try those and see if they work. Cheap/free is the best place to start at. Cost only goes up from there.

 

My 99 did the exact same thing. Consensus was the CPS. I didn't have time to mess with it so I took it to my mechanic. He was getting ready to pull the CPS when he noticed that the wired from the CPS were almost touching the exhaust manifold and melting. Moved them away, made sure they were okay.

Haven't had an issue since.

RSWiser

 

In his 2000 the fuel filter is part of the assembly unit in the tank

 

Certainly no expert here. If it isn't throwing any codes, start at the battery terminals and start checking connections and grounds. Also look for worn/melted wires. Pull connections such as at coil and make sure no corrosion.

Of course you don't "normaly" post here, it's your first post. Welcome !!

 

Thanks for the help guys! Looks like I've got some searching to do and my work cut out for me. It would be awesome if it was something as easy as problem wires.