95' Lumina won't stay running

I recently replaced the 3100 engine in my 95' Lumina Sedan with a 97' 3100 from a Skylark. Everything seems to be hooked up correctly but when it starts it will only run for a couple of seconds then die. Fuel pressure is good, it has spark because its firing and running for a bit. I have double checked all electrical connections for corosion and all contacts are clean. Does anyone have any other ideas I should try. Much appreciated. Jeremy

'95 and '97 used two different OBD systems, and ECM's...different sensors, etc...completely different level of feedback control.

Too much to list specifically, but the car needs to use the original '95 system with all pertinent parts transferred from the old motor to the newer one, or the newer engine's complete wiring harness, ECM, tranny, fuel system, etc...

Now did anything get swapped to make it think it's still a 1995 OBD1 system?

Jeff, thanks for the reply.
No, I did not change out any of the harnesses, ECM, etc. All of the plug ends matched up and plugged right in, I did not realize that the OBD changed from 95' to 97'. So I should be able to change those out and get this running??

Jeremy

You prolly should still get an opinion from Maxwedge or Richtazz...but that'd be my guess...some kind of conflict in the feedback system...

If all the harness ends seemed to be correct, you might just need the '97 ECM...can you still get it from wherever the motor came from? Or maybe the EPROM chips will swap out?

I'd always try to get that and an engine harness when buying a used motor, if possible....just to be safe...

PS what's the build date on that '95?

Just wanted to give a quick update on this. I ended up swapping the intake. I put my old 95' intake and upper plenum on the 97' engine, it fired right up. Sorry its been so long.

I do have one other question though...
The temp. sensor at the "gooseneck" / thermostat pluged right in but the secondary sensor that used to connect at the rear head does not exist on the 97 head. Does anyone know where that should hook-up. My temp. gage does not currently work, nor do the fans. Not a big deal as long as I'm not in traffic LOL.

Jeremy