1996 Chevy Blazer Engine turns over but will not start.

I have a 96 Chevy S-10 Blazer that has a starting issue. When the engine is cold (in the morning) it just cranks over and doesn't try to start. However, when I spray starting fluid into the throttle body it fires right up no problem and it continues to run until I turn it off. The engine will then start again while it is still hot. When I did get it to start, I took it for a drive and it has a very slight stumble at the start of acceleration. I have replaced the coolant temp sensor, throttle position sensor, and fuel pressure regulator. The fuel pump and fuel filter have roughly 16,000 miles on them and I have the proper fuel pressure. I also did a check to make sure I have a spark at the coil and plugs and I have the proper spark. I have no engine light on. It also has a new timing chain that is only 3 months old(don't know if that means anything). What could be the problem? Thanks in advance for your help.