Starting up not going to well
 

Well i just finished hooking up my rebuilt motor and am trying to get it started. It starts for mabye 3 seconds then the check engine light comes on and it stalls. I heard these motors are a bitch to start up so it might be normal but it doesnt seem to be improving at all. If anyone out there knows what might be causing this or where to look your help would be greatly aprretiated because i am very anxious to get this thing up and running again. Also i dont know if this would have anything to do with it but on the ignition coils, does L1 go to the front or rear housing? The manual only says that they should be marked to prevent mix up but unfortunatly i have no idea where they went before.

L1 is the lower hole on the front housing.

what codes do you get from the ecu?

I got what i thought was 45 but there are no codes for an s5 n/a with that code. Ill try it a couple more times and see if i just messed up.

Simple search found that out.

Starts... then dies?? Have you tried starting it and throttling it a little to keep it running? If you throttle it to keep it running and you can slowly get it to keep and hold an idle.. I'd check the Water Thermo sensor (especially if it's cold where you're at). Maybe you forgot to plug the hose into the back of your Intake Piping? That'll cause the car to just die after it revs up on start...

Can't think of anything else off hand, just going from personal experience with start problems.

It might be a vacuum leak. I know when I had one I had to keep the revs up or it would stall pretty quick. Have you tried giving it gas on startup?