Hi all! I'm a bit new to the forum, kinda rude to introduce myself with a question, but I've started to have some problems with the good old Runner You know how if you try to accelerate and you are in too high a gear - how the truck kinda lurches until you shift down?? Well that same feeling is coming whenever there is a load on the engine, such as a large hill or accelerating onto the highway. For example, in 5th gear at 60 mph if i'm going up a hill the engine lurches. Could this be spark plugs or the MAF? Or is it a more serious issue like the clutch? The rpms don't jump when this happens. Thanks!

 

One possibility
~ A couple years ago i tried to take some slack out of my throttle cable, and a few months later i started getting a CEL for Throttle Position Sensor, however the truck didn't drive any differently until just recently.

 

4 Cyl or 6 Cyl? What year? Sounds like you are on the right track. Check spark plugs, air filter, look for loose vacuum lines, check MAF, maybe fuel filter? A worn clutch will usually cause the rpms to speed up momentarily but worn or broken damper springs can cause lurching or bucking under load. I would start with the easy stuff first. Another thought, my Mazda 3 would sometimes buck under load & it turned out to be a bad motor mount.

Paul

 

It is a 6cyl, and with 128,000 miles i really need to give it a tune up, do you think it could be the TPS sensor? What exactly does that do?

 

TPS is a Throttle Position Sensor. It detects the position of the throttle for the computer. Just read a post on a Mazda 3 forum where someone had a similar problem. He had a damaged wire from the MAF sensor. If you have any mechanical skills, get a Chilton or Haynes service manual and perform a full tuneup.

Paul

 

yeah i'm an alldata member so i'm going to plan on spending a few hundred and replacing all tuneup related items. I'll let y'all know how it goes!