I´m having some weird problem with the car cant figure out what it is.

Car was running just fine, but after hearing a weird noise i found out i had a missing alternator bolt, which was causing noise cuz it was a lil bit loose.

Bolt was put in place, drove the car home just fine...went for a drive a few hours later and the car wouldnt start..i mean it would but it would die right after. I had to rev it a bit till it would hold idle and after that it was fine.
Still it would idle at 1500-1600 sometimes and after that it would go back to 900-950.
Today i decided to remove the iacv valve for a lil cleaning and after installing it the problem persisted....car wont hold an idle and if i shut it down after being warm it will die again.......Any suggestions on what it could be? the only thing done to the car was put a bolt in the alternator lol

No cells, no nothing....help?