So I have a 93 jeep xj country 4×4 4.0 automatic. My issue is during acceleration, sometimes when I romp on the gas it will put me into my seat and other times I have slow acceleration.... and when I hit freeway speeds over 65 I have slow acceleration? It's a rebuild motor with 4,000 miles on it and the problem was there before the engine rebuild and it shifts up and down just fine