major problems: 93 4.3l vortec

I have a 93 gmc 15 (same as blazer) that I've been working on for a while. It wouldn't start when cranked, but if I put gas in the intake it would fire and run. When it was warm I checked the timing, dead on.

If shut off, sometimes it would restart some times it wouldn't. I thought it was the injector, so i replaced it with a new one I got off ebay.

Now when Its cranked over, it gets flooded. So much that if I do get it to start (running rough) it blows gas out the tailpipe.

I already checked for leaks coming from the new injector, none. The truck has had a full tune up. No codes showing. The scanner I have show that all of the readings that the ecm sees are good.

I'm lost. Has this ever happened to anyone else? New bad injector? Bad ecm?