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I see alot of people are having problems with there ludes idle. For some reason the h22 and h23 are very sensitive motors. You can change just one thing and the idle surges or stays to high. This is one thing you can do to try to help with the idle i know it works because i have dun this on my lude and many of freinds lude.
Prelude Idle Air Control Valve Bypass Procedures
NOTE: This is a disclaimer saying that I'm not responsible for any damage caused to you, tools used, your car, your mother ,hamster, or anything else for that matter. I have not tested this mod in temperatures under 40 degrees F. If you can please let me know how the engine reacts to freezing temperatures. This mod is something that you choose to do at your own risk. With this aside good luck have fun and I hope it helps you.
Does your prelude idle fluctuate up and down? Chances are your Idle air control valve has gone bad. There is a quick and free way to bypass this with some simple steps below:
How to Check if your Idle Air Control Valve is bad
Start the engine.. let it warm up to normal operating temperature. With the engine running at idle, take off your intake place your finger over the lower port hole in the throttle body (See Picture below and notice the lower hole on the left side of throttle body)

Click to Enlarge any picture
By placing your finger over the lower port, does the idle return to normal? and is the lower port sucking air? If so then you need to do this mod.
If your Idle Air Control Valve is bad / not working lets begin:
  • Remove the four bolts holding the throttle body on.
  • Remove the three bolts holding the idle air control valve on (Be careful not to damage the seals)
  • Unscrew the valve from the housing
  • Take the valve apart - by unscrewing counter-clock-wise
  • Your going to need to reverse the spring and the clip, so take off the metal plate holding the spring, take the spring off, and turn the metal plate backwards
  • Put the spring in the housing first, then screw the valve back in w/ plate reversed to catch on spring. Do not overtighten, just tighten till its closed.
  • Your valve should now look like mine with it closed, if not check that the spring is on the plate properly. Notice the slight bend in the spring now that its assembled, pushing the valve closed.
  • Put the seals back on the valve and put it back together with the three bolts
  • Screw the throttle body back on, and you're done!
 

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That's not even the IACV.

If you really want to just get it closed I would suggest cutting out a piece of pop can and using it as a block off plate.
 

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Yea, thats not your IACV, the IACV is on the front of the intake manifold, not on the throttle body at all, its more near the fuel injectors.

THAT, is your FITV, Fast idle thermo valve. And all you have to do to fix it is screw the valve back into place. then put that little plate back on the end of the FITV and put the FITV back onto your TB. Oh, and i just noticed, you didnt not bypass it at all. Minus the fact that you switched the spring and plate around, KEEP the spring and plate in the valve itself and fix it. The cause of the surging idle is the fact that valve becomes loose so its always open, All you did was fix it just like i explained above, Now the valve will be shut until the coolant builds up enough pressure to open it, ie when the engine warms up and stops the high idle, hence the name Fast idle valve.

I would suggest if you plan on blocking it off, to go buy a 10$ block off plate meant for this, and connect the two coolant hoses together. Thats a true bypass
 

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You copy and pasted this from a link in the recourse thread..
 

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Discussion Starter #5
You copy and pasted this from a link in the recourse thread..
No i copy and pasted it from a link on 92prelude.com I guess i should have looked at it closely and corected it befor I posted it i never realise it had IAVC and not FITV
 

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I have a 93 prelude h22a 2.2 vtec if my air idle control valve is going out are went out would this cause my car to have a constant idle of 4000 ? It idles at 4000 as soon as I crank it . Please help
 

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isaiah

I have a 93 prelude h22a 2.2 vtec if my air idle control valve is going out are went out would this cause my car to have a constant idle of 4000 ? It idles at 4000 as soon as I crank it . Please help
when yours went out did you lose power. it seams like the air fuel ratio got messed up
 
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