HELP!!!! 97 GTP Won't Start!!!

I am in need of some help, I am working on a 1997 Grand Prix GTP with 135,000 miles on it. It sat for about 1 year and was running rough so I changed the fuel filter which helped some. I then chaned the air filter in the car and it will not start since. It turns over ok. I have checked and have a good strong spark, good fuel pressure, but do not have a injector pulse to the best of my knowledge. I plugged in a noid light and it does not light at all while cranking. I did notice that the ecm is in the airbox but I did nothing unusual when changing the filter. I did not even unplug anything to get the air intake hose loose. I have worked on ALOT of cars and am very puzzled as I have never had anything like this happen. I have checked all of the connections on MAF, AIT, TPS and all are ok. PLEASE HELP my neighbors are getting pissed that the car is just sitting in the way Thanks Timmy

Did you double check all the harnesses at the PCM? you may have pulled something loose when changing the air filter.

Yes I checked and the connectors on both seem ok. Thanks for the help though. Timmy