I'll second this. Also, what do you mean by 'it shuts off as soon as I crank'....as in it won't let it crank or it fires up and instantly dies?
Pull a coil offer, slap a spare plug in it and put the spark plug against the cylinder head while cranking. You'll see the ark if you have ignition.
Next is check fueling. You can crank and if you have the means to inspect the ports, see that they're wet. There are other means to check voltage to the injectors.
Before that, you can validate that you have fuel pressure by pulling the feed line, grabbing a vessel and keying-on.
Double check that your MAF is connected and oriented in the correct direction.
Vacuum leaks will usually allow you to fire up but will run like crap or die very quickly.