Are you sure you have the hoses hooked correctly??? Some of the new tractors have the couplers up and down not side by side. So if you have four couplers they are paired up and down not right and left. The reason I am asking your issues are classic hose hooked to two different SCV valves.
Also check to see if you have a bad hose end. I have had them go bad and cause all kinds of odd things.