Motor:F20B
Car:Honda Civic

My car has a high idle of 2000rpms and stays there. Idle screw is all the way in to lower idle.I have a skunk2 manifold with 68MM TB and I am not running a IACV(never gave me problems previously).I plugged up all vacuum ports on the manifold.Now if I put the car in 1st gear, slowly let go off the clutch but dont give it gas,just so I can lower my RPMs,put it back in neutral and the idle stays low.It will stay there til i start driving and when I come to a stop, and car in neutral,it shoots back up to 2000rpms.Anyone ever had that problem or can hopefully provide me with some solutions and things to check I highly appreciate it. NO CEL neither.

 

Problem solved..Had 1 small vacuum leak on the manifold..

 

i have a z6 with a skunk2 manifold and the idle is around 2000 rpm until i tap the gas then it lowers to about 1100 rpm if i pull the throttle (stock z6) back on the manifold really hard the idle drops to a normal idle less than 1000 but i cant tell im not in the car what reasons would a throttle body not close properly and i cleaned it before i put it on.

 

Will a 97 prelude 2.2 intake manifold work on a f20b? I have the same surging problem. Checked timing, check for vacuum leaks and found a small amount of smoke leaking from the driver side of the intake and near the throttle body when my shop did a smoke test. They can't seem to figure anything out because they not familiar with JDM engine swaps. I need help! U can smell fuel in the car because it's running so rich. We replaced the PCV and oxygen sensor. Not communication from the ECU because it's obd1. Not sure what ECU is in the car and didn't even realize it was a f20b engine. Bought it for 500.00 because it didn't start. Once the starter was replaced that's when I noticed the surging issue