E.honda!

94 Civic EJ1 D16Z6 Everything is stock except for the CAI and the BS exhaust.
bought it like this. Originally it was having an issue starting which turned out to be some idiocy from previous owner. Fixed it and she ran like a champ.
Started overheating and previous owner said she leaked coolant. Come to find it head gasket was bad. I changed it CORRECTLY because it was redone once before incorrectly which is why it was leaking. And recently before I purchased it too. So I redid that, and valve cover, cam shaft seal, all that good stuff. Noticed the iac was dirty real bad, didn't want to take the chance do I swapped it for a newerish clean one I had from an uncle who has a ej1 as well. He told me to eliminate the fitv as well due to us living in Texas it's unnecessary due to there not being a single cold day ever down here. Didn't do that originally.
After changing the head gasket and torquing EVERYTHING to spec she started up even stronger and ran like she was coming out the lot no problem. Drove it to a friend's house and back with a few hours in between arrival and departure. Total drive time was two hours. When I got home I parked it and didn't do nothing else. Next day she doesn't want to start. Noticed the fitv had lost the cover for the pellet side. Feel into the frame underneath the engine bay (super lucky) lost the o ring however. Sealed it up with rtv and nothing. Still hasn't wanted to start back up since. She cranks super strong. Backfires a bit due to the exhaust being crap. Previous owner welded straight pipe to cat cuz he thought he was cool. Was like this since I purchased it and like I said originally and day one with new head gasket it ran. So I can't imagine the exhaust being a factor. I have spark, fuel and air but all she does is crank. Any suggestions?