Lost of acceleration power, no power going up a slight incline. however in park engine runs a little rough, but will accelerate but when put in drive has no power

if you accelerate to 2240 rpms and the vehicle moves slowly then everything is not right in the transmission
disregard the dash board fault codes and have the codes read at the data collection point. At a rough guess I would say that the transmission oil level is very low and needs changing or topping up.

Sir if the starter is not even turning im sorry to inform your engine might be broken. Lack of oil could be the reason. I d reccomend to send to a mechanic shop inmediately.

Rough Running Engine - James on Engines #2 - Bell Performance

https://www.bellperformance.com/blog/rough-running-engine

Apr 21, 2015 - When diagnosing an engine with a rough idle, there are certain things that must be ... If the problem does not reoccur, the codes will be erased by the computer. ... when accelerating the vehicle, which causes a higher fuel demand. .... it was water in gas...added added Gas LineAntifreeze/Water Remover.

needs a tune up, plugs wires air/fuel filter will cure this problem

looks like not enough fuel pressure, check the fuel filter.
and the fuel pump pressure.with car running 60 psi
the pump is located at the rear seat driver side you have to remove the carpet to access the cover. if the fuel pressure checked "OK" suspect defective maf sensor (sometimes defective maf sensor do not show errors codes)another way to test is disconecting the maf sensor and start the car (computer goes to limp in mode) and works little better,or check by scanner idle= low grams per seconds and increase when accelerate.

how about putting the van in drive with one foot down hard on the brake and rev the engine, does it smooth out now? if it smooths out, i would pull the air cleaner tube to the throttle body and spray the throttle body with carb cleaner, be careful if using the red tube, I have had it blow off before into the intake, not good, open the accelerator and spray it out really good, it will to start until all the cleaner clears out.

More information needed. It could be because of a tire with a separated tread, an ignition miss, a bad spark plug, an engine problem. With so many possibilities you need to define the symptoms better. Does the engine run rough when accelerating with the transmission in park? Does it go away at higher speeds? Has it been worked on recently and deeloped a problem after that? Did it start suddenly? Is there a loss of power or difficult starting? How many miles are on the engine?

The charging system is doing its job It seems to have an electrical short which is draining the batt. If u have the know how to ck & repair electrical shorts then go after it, if not, take it in.

it could be a clogged catalytic converter.it will cause loss of power and make the engine struggle to get up to speed...

when a vehicle has sat for awhile i put 93 octane gas to clear away the buildup