Sounds like a sticky throttle plate to me and given the fact no engine lamp on I hardly believe a throttle pot failure. You should be able to remove throttle body and clean with carb cleaner and rag however be careful of spring tension on butterfly ( it is strong and unforgiving to fingers). I would also check all hoses to regulator and balance tank (located on fan shroud or radiator, two hoses) Congratulations on your business adventure,BEST of Luck