please send me your savegame and i can take a look what might cause this, do you have any other mods installed?This is the problem. I dont have the ECU mod installed. Not even downloaded it.
Once I turn off the engine this issue starts. It goes back to normal only if I quit to menu and reload.
I noted that reaching 7000rpm the engine almost refuses to go beyond. It is more evident with higher gears. The tachometer suddenly shakes and the engine loses a lot of power on 7000 rpm at the point is impossible to reach 8000rpm on 4th gear.
As the pic shows, it wont pass 7000rpm
attach your output_log.txt too so i can take a look at the mods you have installed