I have two ptac units, both want to run 5 or 6 mins. and cut off

Make sure there is nothing in front of the units, Chair, Couch ect, if you take the cover off the Units, you will see a little black Thermoster attached to the coil.
If the air bounces back off of something then it will cool that Thermoster and shut the unit down before the desired room temp is acualy reached.
Also make sure your Thermastat control knob is turned far enough to the right so that its asking for more cooling, Or desired temp.

Hope this helps.

Good Luck!