in order to help diagnose your problem, i think we'll need a few more details. all i got from reading your post is that "it won't run". how many miles are on your van?
first off, is the check engine light on? even if it isn't, have the van scanned for codes. or if this may be the case, do you know specifically which codes are currently stored in your van's computer?
secondly, under what conditions is the van not running? does it just die shortly after your start it? or dies it only die when idling, or when accelerating, or....????
with that said, an engine needs three things in order to run...fuel, compression, and spark. make sure your spark plugs are clean, and replace them if need be. might be a good idea to replace the wires too. if you have the proper equipment, you can run a compression chekc on each cylinder to verify that the engine's internal parts are in check.
also, what exactly did you do to your intake? did you replace the lower intake manifold gasket?
like i said, more details are needed to be able to tell (or at least make an attempt to tell) what might be wrong with your van. it could be about a thousand different things. | 
