i feel the engine is hesitating a little in i believe 3rd gear but once i get to 60/65 or so once i start cruising at about 65 or 70 or so it run fine. could this be spark plug/wire? i ran the self diagnostics for automatic transmissions and was all clear. i had a fuel injectior go right when i and had just that once changed. transmission rebuit at approx. 60,000. any suggestions would help