Hello..i bought a 4 door integra and well its a nice and strong 5 speed but when i rev above 4k rpms it puffs out a black smoke and smells kinda burned..im wondering what that can be..as well as when it idles it puffs a little smoke and when i turn it off on certain moments it wont start and take a while to go back on! Help anyone please?

 

Does it smell like burnt oil or fuel? Either it's running really rich or you may have a engine on it's way out. Go to harbor freight and buy a compression test gauge for $20. Pull the fuel pump fuse and crank it with your foot to the floor on the gas pedal. Hopefully all four cyl are close to the same psi.

 

dam hope it nothing big good luck