This is a Portable dishwasher, the unit fills and drains and the pump motor runs - however I don’t belive that there is full preasure during wash cycles not sure if the spray nozzels are turning and it does not sound like full power - I have taken it apart and clean all the parts in the tub and noticed alot of garbage in the filter. Could the filter be the problem or could it be other itiem?
Here are your parts
Replacement parts for MAYTAG MDC4650AWB | AppliancePartsPros.com
Here is a service manual and a tech sheet
http://www.servicematters.com/maytag_library/docs/16026945.pdf
https://www.servicematters.com/docs/wiring/Tech%20Sheet%20-%2016026897.pdf
Did you open the pump up and clean the filters, etc.
If not I would start there.
You will probably need a torx driver to remove the pump covers/filters etc.
Also check that the holes in the wash arms are clear.
I find the easiest way to clean them is when the junk is wet and then pull them out with a pair of tweezers.