Ranger Jerking at highway speeds

[byrc]

Alright I have been dealing with an issue for a while now, and I am out of ideas. I have a 1993 3.0l V6 Ranger with 224,000 miles. Recently I have noticed that on the highway at around 50 MPH the car starts to jerk strongly, as if it is misfiring. Furthermore, the RPMs fluctuate greatly during these jerks, between 2000 and 3000 RPMs. Additionally, I have been experienced rather rough idles, and the tachometer also jumps while at idle, though not as greatly. While driving in the city, it runs pretty well, a little rough but nothing to worry about but I can barely drive on the highway, let alone pass anyone. Also, the check engine light comes on sporadically, but turns off after a minute or two. So far all I have done myself is replace the fuel filter.

Also, when on the highway, the jerking and RPM jumping seems to subside a little if I push the accelerator more. I am not very mechanicly inclined so I am sorry if my post lacks needed info or anything, I am just out of ideas, and hate the idea of getting rid of my ranger.

 

[Beef52751]

i would check for stored codes.
Beef

 

[Blackedge03]

My father-in-law had the same problem was an o2 sensor. Get the codes first. They will point you in the right direction.

 

[etemplet]

Sounds like my 1991 2.3L. It's been doing that for years. Let me know what you find/found out.

 

[funkingonutz]

yeah mine "burps" once and awhile at a sustained speed....but mines less noticable....feels like what u said...like it missing

 

[shaffer20]

with 224,000 miles i imagine it could be as simple as engine sludge/gunk. run through some seafoam its an incredibly amazing carbon/sludge clenser. on a protege forum there was a guy that had a piston slap issue. he ran some seafoam through and hasnt had the problem since. put 70,000km on his car since. but i cant stress enough only use one bottle, i have herd of people hydro-locking there engine because they decided for whatever reason to use more then they should have. there is a seafoam board on this site. browse it and see if anyone has found a better intake hose to use other then the brake booster line as depending on the engine it may not spread evenly through the intake system. you put 1/3 of bottle through brake booster line turn off engine put 1/3 in the oil and 1/3 in the gas tank. wait 10 min then start her up and give her the gas and watch 224,000 miles of sludge fly out your exhaust.

http://www.youtube.com/watch?v=u-Ei...D6AE3D25F&playnext=1&playnext_from=PL&index=5