I just completed a swap of my bad 2.3 h23a motor to a japanese purchased 2.2 Dohc F22b...the car is a prelude SI with automatic transmission...I used the original ecm,distributer, throttle body, fuel rail and ac compressor on the new motor...The engine runs but it races up to 1900 rpm and drops to 1500 rpm continuously....The check engine light is not on and there is definately no vacuum leaks...can anyone help me with this problem...I've been told it's many different things but to no avail...HELP!!!!!!!

 

bleed your coolant??

 

It could be ur fast idle air control valve its usually located under the throttle body.

 

i've got the same problem w/ my stock h23... it's probably your idle air control thing... that's what it is in mine.

 

take your intake off there will be a hole in the tb on the lower left side put you finger over it, it should idle fine once you do this... If it does take it the iacv off its only 3 bolts and you will need to take the plate off holding it on by 2 screws. You will see a white piece in there with to groves to put a flat head screw drive it it... turn it clockwise till it wont turn anymroe careful not to break it and tigthen it to much. Back it off a lil after it gets tight put it back on and idle should be fixed.

 

The H23 ecu looks for a knock sensor signal. The JDM F22B doens't have one

 

Hey man I JUST did the same thing, only mine was a manual trans, the reason (I think) you're RPMs are pulsing is a bad idle sensor or Idle Air Control valve, either way it's in the throttle body and the whole throttle body needs to be replaced, or u can try adjusting your idle a little... I'm have a major issue with over heating with my f22

 

^^ I finished my swap today, runs like a 100 bucks. I reused my whole original intake manifold, ingectors, fuel rail, and throttle body set up....it works like a charm.

Biggest obsticle was was having my power steering hose relengthened