Please help me with Mustang 5.0l

Yes, check the TCC, disconnect it electrically, if you have Oscilloscope Look at the signal. According to my understanding, the TCC should only work on D, and there also only in the high velmas. But as you eat the most, it fails to put it in R, so I think this actuator is failing you.
Before lowering the box, the lines of the lines?
How did they come out?

Greetings from Chiapas.

Thank you, I did not have the suspicion that the fault was in some component of the box when I dropped it, I did this to change the turbine, clear passing pastes and more. But do not check the pressure of the lines before lowering it.

Hello, you have already tried the sensor voltage and fuel pressure. If the problem is that if you manage to walk a few meters or accelerate it if it works, try changing the MAP sensor, this sensor does not come out in the diagnosis when it gives problems, try with another if your engine has this sensor.

Hello,
I hope it helps you is a comment if I remember remembering your transmission is a 4r75 with OD. of computer control that is managed by the ECA.
You have reviewed a transmission specialist is possibly the control of the TCC.
that when applying the induction force is the cause of blocking in the Torcion converter
is not that this is but the possibility fits

Small error 4r70 was a small skid. You know the brakes and high speed or do not for anyone and you love water. but in short
I send you the manual to have yes if it happens