So i have an 89 Trooper II with only 86k original miles maintained very well and was barley driven by the previous owner. Anyway it has a knock when you just slightly press the gas peddle or when it gets over 2800ish RPM. Does this both in and out of gear. Anyone ever have this problem before? If so what was the fix?

it might be the lifters need adjusting they need re-adjusting about every 50k or so (if you have the 2.6 and smaller engines)