Post your annoying bucking symptoms here

[nofordstranger]

Can't Stress Enough - Only Autolite/Motorcraft Spark Plugs!!!

Seriously! Find out what plugs it had when it came out of the Ford Factory, and replace with exact same plugs! All these Fancy New Platinum tip plugs like Bosch and the rest will only give you headaches. From the very first time I tried these types of plugs about ten years ago, I could tell the difference in performance immediately, without even driving it. Put the originals back in and good as new in comparison.

 

[powerranger262]

They are 5144 Autolite Double Plats. Serioulsy.

 

[wynnespeed]

Mine started bucking kinda like the but it doesn't skip at idle though, I put heat in it and that didn't help, still gotta check the plugs though

 

[appletonbill]

The other day as I was on an uphill on-ramp to the freeway in OD as I got to about 55 the engine bogged down and then died. I got it over to the shoulder, waited a minute or two and it started right back up and I went on my way. The fuel filter is less than a year old.

 

[Jacks2K4x4]

Sorry to bring back an older thread. I just purchased a used 2011 (56,000 miles) with the 4.0 and starts bucking only when there is snow in the air. Really weird. In fact, yesterday was sunny and windy. A couple of times snow was blowing across the road and the truck did a slight buck when it went through that section of blowing snow. Air intake looks and feels tight. I've read elsewhere it could be an aftermarket air filter not seating proper. I'm going to try a Motorcraft filter to see if it helps. Anyone here with the SOHC 4.0 have or had the same problem?

 

[RedRangerSTX]

My '02 Ranger FX4 (4.0L SOHC w/5spd manual) used to do the exact same thing particularly when it snowed. You have an air/vacuum leak of some kind somewhere. In my case, the cold air intake that was on my truck when I bought it was junk and must have been allowing fine snow flakes to mess with the MAF sensor... I put a stock air box and filter in, and the problem went away. Recently, however, I noticed it again. The truck would buck randomly once in a very great while. Just last night I noticed my PCV hose elbow has a hole in it, which I am confident is the problem. Very common issue on the 4.0L SOHC motors. Check yours and make sure you pull it right off to inspect. The hole in mine was underneath where it was not immediately evident. This thread has some nice pics of it: http://www.ford-trucks.com/forums/924974-banging-my-head-against-the-wall-fuel-trim-system-lean-bank-1-and-2-a.html

Mine looked like this:

Couldn't hurt to spray your MAF sensor with some CRC MAF cleaner too.

 

[Jacks2K4x4]

Redranger, did you get a P0171 and P0174 code before finding the hole in the PCV hose? My bucking has seemed to stop after fiddling with the air cleaner, opening and closing. I am going to bookmark this thread for future use, though. My 2000 ranger had the above lean codes before trading it in for my 2011. Thanks for the info.

EDIT: I saw you had one of the codes in another post.

 

[RedRangerSTX]

I got a P0171 code for Bank 1 running lean with the hole in the PCV elbow, but strangely not the P0174 code for Bank 2... I have since replaced the PCV hose and both the lean code and random bucking went away.

When my cold air intake was causing the bucking issues during snow, no codes were thrown.

Basically if unfiltered air is getting sucked into your system in any way it seems it can provoke that bucking.