help dx to si problems revs bounce at idle

i have a 90civic hb swapped a d16z6 head on it. car runs and drives up to 3500 rpm then cuts out. vtec is not hooked up yet.at idle it revs to 1500 and then drops to 500 then back to 1500....i have checked for vaccum leaks and can not find any. i am runnin a 90 si comp,94 ex intake,94 ex distro this car is confusing several master techs? if you have done this swap please respond!! i have to work at five

i have a 90civic hb swapped a d16z6 head on it. car runs and drives up to 3500 rpm then cuts out. vtec is not hooked up yet.at idle it revs to 1500 and then drops to 500 then back to 1500....i have checked for vaccum leaks and can not find any. i am runnin a 90 si comp,94 ex intake,94 ex distro this car is confusing several master techs? if you have done this swap please respond!! i have to work at five
my car did that it's your idel air control valve.i think anyway ,there is is this peice that comes loose in there and it lets coolent in well the when it gets loose it lets it in,well the it freaks out and thinks the car is cold so it jacks up the idle and as soon as it does that it all goes out idel goes down and then it does it all over again and again my car did that forever and my buddy told me about it it worked good luck

My Civic was doing the same thing after a rebuild on the Head. It turned out being the Idle Control Valve. Follow the steps in your Maintenance manual to adjust the Idle Control and reset the ECM (ECU). I did and it worked like a charm!!!!! Good Luck.