I just got done doing an auto to manual swap and also a f22 to H23 swap in a 92 Lude. Everything works and the car drives but the engine idles at 2 grand and when you hit the gas it bounces from 2000 to 4000 and then to about 300 (at which it sounds like it is going to die) I have taken to my local import shop and they don't think it has a vacume leak, we replaced the trottle body gasket, put a working fast idle valve from another h23 on it, and they and myself can't think of anything esle it could be. I pulled this motor from a wrecked Lude, but the engine still fired up (rear end damage) so I know the engine was in perfect working order. If anybody has any other ideas on what to try to correct this problem would be great. Thanks

 

Did you put a new timing belt. If you did, you should recheck your timing.

 

i think it might be somethin with the transition from auto to manual, because i did that with a b18 and it might be something with the egr valve?

 

Other than the fast idle valve, also try replacing the Idle Control Valve.

 

my prelude has a similar problem, after beating on it the idle will jump up and down rapidly when the car is at rest. my car has 150k miles and erveryone has told em it has to be the ICV or FIV.

good luck finding the problem.

 

idle control valve... also, try adjusting the idle screw