I have read these boards along with a whole bunch of others trying to get ideas and avenues to try and solve my 2001 Ranger FX4 4x4 x-cab 4.0L manual 5 speed engine mis. No check engine light, no trouble code, no pending codes. I have had the truck for only 2 months. Symptoms were: engine mis (buck intermitantly) Thought it was originally a bad tank of gas. As it turned out, it only happened when the roads were wet either from rain or wet snow. As soon as the roads were dry, the problems went away and the truck was running and acting great. I tried putting new spark plugs and new spark plug wires on and a new air filter. Seemed a little better but still had the engine mis (buck) when the roads were wet. I checked the coil next. No visible cracks I could see. I measured the secondary resistance and tried to compare my readings from other coils and got quite a bit of variances. So I didn't know what to do. Buy a new one for $150 just to see if it works? I called dealers trying to get answers and didn't get any. All they could tell me is it gets checked when they plug in their fancy shmancy code reader and it comes back either good or bad. I tried lubing every connection I could find with di-electric grease. Still not getting anywhere so I finally reached the point of bringing it in to the dealer to get looked at. I don't give up easily mind you and bringing it in made me feel like I failed. They had it all day and did all their fancy shmancy scanning and wet down tests and fuel injection tests and flow tests and spark monitering and driving it through the car wash and could not duplicate my problem. I informed them it would be difficult to find the problem and don't look at the usual easy stuff. Dig deap to try and find the problem. No luck, they found nothing. (kind of hard to stay mentally strong when you spend some decent money on a truck that you don't even feel like owning anymore after all this). 1 idea off of this board was to try and change the gear lube in the rear end. Maybe the friction modifier has broken down. I have 4:10 gears with a limited slip differential. At this point I am willing to try anything. At the same time I also decide to put a new coil on. I mean what the heck, why not at this point. After doing the rear end and the coil. My problem is gone!!!!!!!!! Which one fixed the problem I don't know for sure. If I had to guess I would say it was the coil. Someday I might throw my old coil in to see if it bucks when wet outside but right now I am just happy to have my truck back running great in all weather conditions. I just wanted to say thanks for having a place to share stories and ideas and suggestions with. Good luck to all you guys.

 

Thanks for the info and glad your truck is running good again.

 

That's weird. I think my truck and your truck are related. Mine is telling me the coil packs are bad, and they aren't. Your coil pack was probably bad, and you weren't getting a code. It's some kind of telepathic connection.