Hic-up/Jerk in 5th from 55-70 mph going Uphill
2003 Ranger,4 Cylinder, 2WD-72,000 miles
I was making an 800 mile drive recently and noticed a strange problem WHen cruising at highway speeds and going uphill the truck would sort of hic-up. No noticable difference in noise but the truck would sort of jerk. When I downshifted to 4th at rapped it out, no jerk. This went on until I reached my destination. Driving around town, no problems.
On the return trip home I had the same problem. This time I also noticed it under hard acceleration trying to merge into traffic. Whenever I tried to go uphill, same thing. The problem became more frequent the longer I traveled.
Now driving arount town, no problem. Placing any sort of load on the drivetrain, the jerky hic-up happens.
Things I have tried: Code Reader-No Failures, replaced gas, fuel filter, utilized 2 doses of fuel injector cleaner, new spark plugs, new wires.