I just recently fixed a problem almost identical to this. Symptom was the car intermittently going out on low oil. There was nothing wrong with either the valve or the oil level.
Two other things you could look at:
Check to see if the top emergency limit is dirty or failing. This is the one between the top terminal slowdown and the up normal(directional) limit. You may not have this if your speed is lower than 150 ft/min.
The other thing, which was the problem in the unit I just fixed, was the one auxiliary "M" contact on the starter relay intermittently failing . What was going on is that the starter was energizing the pump but not getting power to the up valve solenoids. After about 40 seconds the unit shuts down on a LOT fault. This "M" contact is the one in series with your entire up valve solenoid circuit. My unit was using an older Furnace style starter. What I ended up doing was replacing the "M" aux contact and then adding a parallel relay with the starter which gave me a means of adding a couple of contacts to parallel that one starter auxiliary contact.
