I bought a 1991 Honda CRX and the kid I got it from had put a D15B2 engine in with a Y8 intake manifold it has a multi point fuel injectors and is having an idle surge problem. I switched the IACV but that just made it not idle as high from what I noticed. Any help would be great I don't want to end up putting in a ton of money if it's not worth it. Thank you!!!!!!

 

You need to do a few things:
-take the IACV off and clean it out really good. When you think it's cleaned out, clean it out two more times.
-put the IACV back on and bleed all the air out of the water lines. You can't have any air pockets at all or it'll surge. With the rad cap open, rev the engine up and down and cycle the heat on and off to help move air away.
-set idle with the IACV disconnected (unplug it). Then turn the car off, pull the battery cable off for 30 seconds, plug the IACV in and connect the battery, and start the car.

If it still surges, consider another IACV. When mine went bad, I grabbed a couple from the junk yard, cleaned them out and swapped them out until I found one that works. They should be pretty cheap.

 

Okay man thanks a lot i will try that out tomorrow. But if that does not work for whatever reason do you have any other suggestions?
Again thank you