I have a 2001 Pontiac Montana and the self leveling system has the van stuck in the up position. It has been that way 2 days and will not deflate. What could be the problem?

If engine cranks but diesnt staet then Most likely fuel pump / fuel filter has a problem.

on fuel level sensor on top side of fuel tank.

Two things . first cover and piston was place in wrong position or seals are cut or misplace;
second is the transmission is fill at normal level.
hope it helps

find your reset switch and reset it

Hit the starter with a pry bar and hammer? are you out of your mind? Should they re check the duct tape and bailing wire also?

I'm quite certain what your problem is. The fluid level is too low. Now wait, it's not that simple. In order to bring the coolant level to the correct height on this vehicle, ready for this?, You have to jack up the front of the van or drive it to an upgrade that is quite steep. The reason for this is that the heater core is almost a foot higher than the level of the radiator. I found this out by trial and error. Most dealerships don't evn know about this. I'm assuming you've already ruled out the easy stuff such as a bad thermostat or radiator correct? Let me know how you make out, okay? Thanks, Dana.

Hi, you may have a draw in the van. Please see my tip at http://www.fixya.com/cars/r5925550-dead_battery_troubleshooting . These are genericinstructions. If you get stuck or need specific instructions for your car, please get back to me with model, year and engine info.

have wheel speed sensors checke

This is a common problem with Chevy Venture, Olds Silhouette, and  Pontiac Montana. The mechanical wiper drive and parking cam assembly, if it's not broken, needs adjustment. The spring loaded stop arm should engage the vertical tab on the assembly mounting plate when the wiper motor reverses. See pic. 
I will upload the instructions to fix this problem, if there is interest.

Check out www.carsurvey.org for more information on your problems. There are others who have had similar experiences