97 tahoe no start

Hey guys well friday I drove my tahoe to work and did a motorvac de carbon machine to it, cause it was runninga little rough and it has 130000 miles on it. so afte work I come home park, then saturday mourning I go to leave and it wont start, so I checked for fuel and fire, and both are present. I shotgunned it assumig the cam shaft sensor was the trigger for the injecotrs and replaced it, but still no start. It will run off of starting fluid. But do you guys have any idea on what could be causing the injectors not to fire. I'm going to buy a fuel pressure guage today to check the actual pressure while cranking. but any ideas would be great