ok i have a ls vtec and with a b18b 98' block with a 99 civic si head. i am having problems with the car running. it has never ran yet all i can get it to do is idle reallllly bad.and when you push the trottle i sounds like its going to die and then once you let off it will rev and then go back to the normal realy bad idle. the timing i have checked over and over. and i have moved the idle screw and moved the dis. around. but got nothing. i am getting spark and i tryed taking out the spark plugs one by one and every time i was the same as before. i need help bad any one HHHHHEEEEEEELLLLLPPPPPP!

 

hey man i have a setup real similar to yours i guess the guy who put my b16 head on was having the same prob but then he got all the valves retimed and reset and adjusted and it runs almost perfect right now but it could still use another adjustment but yeah try checking your cams, cam gears, and valves make sure they are all in sync. with one another maybe then you should be fine let me know if that wasnt the prob.

 

check the map sensor vacuum line and wiring. could've come off or frayed
Check cam timing. Make sure the cams' "up" mark is up and the pointer on the lower timing cover is pointing to the TDC (lone) groove in the crank pulley (there are also a set of 3 grooves near the TDC)
thats all I can think of now........