IACV issues

[orangeaccord]

Well it worked last night, but I must have a leak in the cardboard gasket I made because after driving it a little longer this morning, the idle started revving again.
I'm thinking I'll shell out 30 bucks and get an IACV and FITV off ebay. Hopefully that fixes the problem.

[Granite CB7]

orangeaccord-yeah, 1200 seems quite high! I had to raise my idle quite abit when I blocked off the IACV. My base idle is 900.

johnl-thanks for the great info! I realize the cardstock isn't the best thing for a long term block plate, but it allowed me to quickly diagnose if the IACV was acting up by blocking it. I have always read that there's alot of ways to rid of excess heat in the IM on a Honda, and it's def. true. On my F22a, I've had the t/b coolant line removed for over 3 yrs. w/ no problems. I wanted to get rid of all the heat sources on the plenum/ t/b w/ my new IM setup. I believe most of Honda's "performance" motors (H22 Euro R, ITR) only use an IACV, no FITV, so I wanted to copy that but not run any coolant through the IACV when it's not blocked.

But the FITV will work fine w/o the coolant running through it? I haven't tried that yet, that could be a possibility! I was mainly concerned w/ ridding of heat sources, so if it'll work w/o the coolant, then great! Would it stay open longer since the heat may take awhile to reach it?

[johnl]

It's well known that a cooler intake tract will heat the incoming air less thus the air will be denser and thus more power potential exists. However, I reckon you'd be struggling to actually measure any gains had from blocking off the coolant lines to the IACV and FITV (a dyno may prove me wrong, but I'd be surprised!).

Heat soak from ambient engine bay temp and conduction from the head would be far greater, but harder to eliminate. A thicker / less conductive intake manifold gasket might be of more help? It's not as if any of the intake tract has a huge heating effect from a large coolant passage as you get with many carburettor manifolds (for better atomisation of the relatively large fuel droplets you get from a carburettor). Any gains from blocking the small coolant flow through the TB, IACV and FITV can only be small at most.

My IACV is totally disabled, and the FITV has no coolant flow through the little coolant lines, and it works perfectly OK, cold idle is high as it should be, but drops back to 'normal' as soon as the needle starts to move up the guage.

I can't see why Honda actually uses the FITV, if you blank it off the IACV will do more or less the same job, detecting low idle and increasing it, albeit not as high as the FITV does, but this would surely only be a matter of programming the computer to open the IACV more under X temp. It seems just an added complcation, i.e. something else to go wrong and additional cost to build...

[Granite CB7]

^Thanks John, I still need to do some more experiementing but it's def. good to know that the FITV operates w/o coolant running through it, I may decide to keep it but w/o coolant! Good info

[orangeaccord]

update

Finally figured it out... I feel incredibly stupid.

Apparently, it had something to do with the TB i used after doing the IM swap. I used a TB from a car with an automatic trans on my car, which has a 5-speed. I did so because the original TB was really sticky. The other day i stuck two fingers in the TB and noticed a slight crack where air was getting into the IM. Bam, replaced it with the old TB and it doesn't lope at all anymore. Still has to search every once in a while while FITV is running, but i think that's just a bad FITV. Thanks for all the assistance guys, I appreciate it much. Now just to go on and fix my instrument cluster, do a shock, touch up the paint, and get a new parking lamp .

[KeeleDesign]

Finally figured it out... I feel incredibly stupid.

Apparently, it had something to do with the TB i used after doing the IM swap. I used a TB from a car with an automatic trans on my car, which has a 5-speed. I did so because the original TB was really sticky. The other day i stuck two fingers in the TB and noticed a slight crack where air was getting into the IM. Bam, replaced it with the old TB and it doesn't lope at all anymore. Still has to search every once in a while while FITV is running, but i think that's just a bad FITV. Thanks for all the assistance guys, I appreciate it much. Now just to go on and fix my instrument cluster, do a shock, touch up the paint, and get a new parking lamp .

dang that doesn't help me lol.
i have posted a similar thread in the members area of technical discussion.

i am at a loss..
i am curious though, why didn't you just adjust the idel screw above the pendilum on your other throttle body, to close the gap that was making it surge.?

[bcjammerx]

readjust your idle...it sounds like it's too high. When the iacv is unplugged the idle will lower...when plugged in it will raise.

when it's high it'll fluctuate. Mine idled like you said until I lowered the idle...of course my idle screw would unscrew itself within a few weeks. I had to use some sealant.

Follow proper procedures and adjust the idle...
1. let the car warm up (fan will come on then go off)
2. Car still running, unplug the iacv.
3. Next use the screw to set your idle. If the screw is completely closed off the car will die, so you will need to unscrew it and start the car again, then keep unscrewing it until it idles around 600 rpms.
4. Then you turn off the engine, and plug the iacv back in
5. you may need to reset the ecu...it's a good idea to
6. the idle should be around 700 after warm up.

Your engine should idle aroun 1500 when cold and after FIRST start then it should idle around 700.

if you don't have any leaks (if any gaskets were not brand new they should be your first site of suspicion) then we can try other things

if it still does it then we'll take it from there...there are some other things to adjust.

clean your tb and everything else, you could even clean your iacv...I don't really see all three being bad as very likely...possible sure...but I wouldn't make that my first guess.