Hip hop ford fusion

Need ideas because we’re at a loss.

We have a 2012 Ford Fusion 2.5L that we had towed to us as a check over after purchase.

The vehicle had a hell of a hop to it. Two coils broken, the exhaust unhooked from the exhaust manifold…. fast forward, the vehicle needed a new engine. We replaced the engine.

NOW

No codes, but the vehicle has a BAD hop (almost like you’re pressing gas/brake over and over again) but only at idle in drive/reverse. In park, neutral and once driving the vehicle is perfect.

I know it’s going to be something shit simple, but I need ideas.