Nothing in the D-Jet would cut fuel at a given RPM, or shifts, which tells me there may be some other issues.
If you keep your foot in it, does it rev past 5k? Or does it just not go past 5k and shift?
Be as thorough as you can, and I'd suggest making a new thread... it almost surely isn't electrical related (Unless you're putting a voltmeter on and see you're like 10V or something ridiculous at 5k RPMs).

__________________
Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k