Surge at 3100 RPM?
 

Just purchased a 2009 totally stock Ranger XL, 4 banger, auto trans, with only 23,000 miles on it. Truck is in pristine condition, but I have a slight problem that I noticed.
While sitting in driveway and letting engine warm up as I rev it up a bit, it is smooth until I hit 3100 rpm's. At that point the engine seems to surge and stumble, and even giving it
more throttle , dosen't want to go much higher in rpm's.
Haven't taken it out on road yet, and gas that was in tank is probably old (unk age). I filled tank up to full with fresh fuel, and will be changing fuel filter on Sat.
Don't think it's injectors or coil/wires as up to 3100 rpm its as smooth as a new engine.
Any sensor/s it might be??? Not showing a code on dash and no check engine light has come on. I do have a OBT code reader, but not available for a few days...loaned it out.
Any input???
Grumpaw.

OK, google is my friend. Did a bit of research and I didn't know that there was a rev limiter that won't let the engine rev over about 3100 rpm when trans is in park or neutral.
Since I haven't been able to take it out on the road, I'm hoping this is my "problem".
After today with new tags, I'll be taking it out for a real "run".
Grumpaw

That is the problem

REV limiter is set for about 3,000RPM and is active when in Park or Neutral but also if speed is 0MPH