So II have a 94 country 4.0 auto. Drove a whole lot over the past few days and it drove fine (minus the station with crappie gas that I augmented withsome premium from a good station). Well on my way home after filling up I added some fuel system cleaner. I know. I should have added before I filled up. Not after. It was an after thought because I had to stop and add oil. Well it drove perfect for about 3 hours straight. Then, sitting at a red light it starts idling rough as hell, almost shutting off. I get it home. It runs like crap any time my foot is on the peddle. Acceleration is a nightmare. Minimal power, rough running, everything. I tried adding some gas to mix up the cleaner but it didn't help. Did I screw something up or do I just have to deal with it for the rest of the tank and fill up with good gas? I'm about to have to tow a light trailer 4 hours in a couple weeks. Need to figure it out asap. I know I probably need to change the fuel filter. But it just changed in a matter of seconds. No gradual progression. Any ideas to check will be appreciated.

 

Throwing any codes?

 

First thing I checked. Nothing. Solid 55 is all I get.

 

1. Change that fuel filter. They're cheap and on your vintage take about 15 minutes to replace.

2. What is the history of routine tuneup hardware? Fresh Champion copper plugs, quality plug wires, cap and rotor go a long ways toward basic driveability.

Start there. Good luck and keep us updated!

 

Clean the throttle body real good. Also check for any vacuum lines popped off or leaking. And maybe check the throttle position sensor.

 

So. Note how I said randomly. Drove it this morning and she's driving perfect again. I was just commuting about 20 mins each way them just drove for about 15 hours in 3 days. Maybe she was just tired. Lol. Still getting that fuel filter but I'll hold off till I relocate for the rest of the tune up. Thanks for all the input guys. I feel dumb not knowing this stuff because I am a vw tech but it's been a long time since I had to drag things without crazy OBD-II systems and faults for as little as a bulb being out. Plus, this is my first Jeep. - sits in corner of shame- Now if I can just fix my vibrations I'll be happy.

 

J,a little at a time.