Doing a swap into a 91 525i with a motor and tranny out of a 96 328. The issue is now where the engine will start and run, but it shuts off. Any more info needed, just ask. I simply don't know what else I need to tell u guys yet. Thanks a lot BTW.

That car had an M20 in it right, that means you swapped the entire OBD2 harness & computer with the M52, if so your probably having EWS (immobiliser) issues. If you did that your going to have a bunch of CEL's also.