Feels like Rev Limiter at 4,500 RPM

[ADEN]

Tps.

[IceyVert]

Our for a drive yesterday and noticed a slight hiccup/hesitation under WOT at 4K and again at 5k rpm. Got home and noticed a loose plug wire. Snapped it back in and figured good to go. Out for a drive today and now it’s much worse. Once it gets up to 4,500rpm it acts like it is bouncing off a rev limiter and will not continue to rev. Does it under both partial throttle and WOT. Under no load it will do the same at 5k rpm. I have a new fuel filter and plug wires waiting to go in. Plugs and air filter done 1,000 miles ago and I checked for vacuum leaks with propane and found none. Anyone have any ideas what to troubleshoot? Car drives fine with normal power up until 4.5k.