91 MGM wagon wont start

Alright, I have a 90 Lincoln with a 5.0 and the MGM has a 5.0 as well. I put the Lincoln engine into the MGM along with most of the wiring harnesses. Have good spark, fuel and will crank just fine. It is just a derby car, but i still cant get it to start. I am pretty sure almost all the wiring harnesses are hooked up as well. Also the Lincoln engine ran before putting it into the MGM. Any suggestions?

Update: I found out it is an injector problem. I have power going to them all and I have continueity on all of the wires running to the pcm. I also switched out the pcm maybe thinking it was bad but that didnt do the trick either. So my two things are this... I dont have a very good ground running out of the PCM, or i think there is a sensor or switch that is making the PCM shut the injectors down. I am going with the ladder option but any feed back on what sensors will do that?