I have had this 1988 Cadillac DeVille Gold Edition for over a year now. It is the 4.5L V8 4D. After about a month of having it, it started having a problem where if I attempt to accelerate passed 45mph it jerks the car so hard it feels like the engine just physically stopped for a split second but then continues. Any time I try to speed up after that it does it, but only 45mph. It does not matter whether it is downhill, uphill, or level. I found a broken vaccum line a while ago and fixed it. I've tried replacing plugs and wires, fuel pump, fuel pump wiring, cleaning injectors, cleaning atomize