Hesitation

[Berry]

I just recently returned from a trip to the Catskills in NY state. Great place to go if you are looking to get back to nature and want to make the drive.
My vehicle is a 1999 T4R Limited with a TRD Super Charger. My TR4 has under 110k and in great condition.
While on this trip I noticed that at speeds of around 50 plus and going up a hill it would start to jerk. I could feel this in the gas pedal and in the rear end. If I gave it more gas on the incline it would disappear and act normally. It would also happen on level ground and again the increase in rpm would basically act like nothing was happening. I could run it at speeds exceeding 75mph and nothing would happen.
I haven't had any problems with my 4R and this was somewhat weird to say the least.
Any clues as to want this may be?
Thanks for your help, and suggestions in advance.

 

[Atrox Caeda]

Have you had any work done on the rear differential?

 

[Berry]

Have you had any work done on the rear differential?

Thanks for the reply!
To answer your question.........No I have not had any work done to the rear diff. Sure hope this is not the problem.

 

[Doc2012]

When was the last time you changed the spark plugs, and what did you use?

I also have a '99 Limited, and while traveling from NC to CT to visit family, it felt like the transmission was slipping. turns out the plugs AND wires were NEVER changed in 150k.

If you changed them recently, these trucks are finikey. Use ONLY NGK or Denso plugs.

 

[Berry]

When was the last time you changed the spark plugs, and what did you use?

I also have a '99 Limited, and while traveling from NC to CT to visit family, it felt like the transmission was slipping. turns out the plugs AND wires were NEVER changed in 150k.

If you changed them recently, these trucks are finikey. Use ONLY NGK or Denso plugs.

I have not done anything since I bought my 4Runner...........which was around the beginning of the year. It was maintained very well and originally owned by a senior Toyota technician.
Some other comments off other forums indicated possible EGR or TPS problems. Do these 2 areas sound like potential problem areas?
Thanks for your response and suggestions!

 

[Doc2012]

In my experience, the TPS would also cause backfiring, running rich, and a O2 sensor code, because it's what determines the AFR. I had one go out, and as long as the RPMs were high, then it would run great; if I were rinning slow, it'd be backfiring the whole time.

Never had an EGR go out on me, so I can't tell you about the sx of that, but its always a possibility.

Those two would more than likely throw a code, however. See if you can find someone with a reader, and check and see if there are any stored codes or anything in there.

Check your plugs and wires. If it's the original wires, try replacing them. If the plugs have a little charring on them, repace them too. Worst comes to worst, you just did some maintenance.