mikep_95133

I was reading wildoutwhitegsr's thread on how to disassemble and clean up the FITV ( https://honda-tech.com/forums/acura-integra-6/%2A%2A%2A-how-%2A%2A%2A-clean-your-fitv-aka-fast-idle-thermo-valve-1564019/ ). My FITV was brand new via the previous owner. But I wondered if they come 'out of caibration' if it's not an actual Honda branded part. The whole reason for even looking at this new FITV is that during warmup my idle surges from about 900-1600 rpm for quite a while before I get a clean idle at 700-800rpm.

So I took the FITV off and just took the top off. Everything was clean as you'd expect. The slotted plastic part was turned out 2 turns from all of the way in. It was very easy to blow through the round hole. With the plastic part screwed all of the way in, I blew into the round hole and it was pretty much sealed off. This would not allow any fast idle as hondadude once pointed out in post #3 of this thread https://honda-tech.com/forums/honda-accord-1990-2002-2/cleaning-iacv-fitv-tb-1844067/. So I backed out the threaded part exactly one turn from all of the way in. Blowing through the round hole again allowed just a small amount of air to pass through. The car was not stone cold, but had been sitting for a few hours. The warmup idle was now 1400rpm instead of the old 1600 rpm. The surging was gone as well. I still need to see if the surging idle goes away after the car has been sitting all night.

After the FITV was bolted back on, I realized that if I didn't like the one turn out adjustment, that all I have to do is to remove the lid and make the adjustment with the FITV still bolted in place. Sweet!! This ease of adjustability is mostly due to where the FITV is mounted in this particular model year.

In this pic you can see the FITV has only two screws holding it's lid on that gives access to easily adjusting the amount of warmup idle or to get rid of surging. The throttle cable just needs to be lifted out of the way. So simple. The FITV does NOT have to be removed to make any adjustments. This pic is just what I had handy for the thread.

aasaa666

The picture you are showing us is the Idle Air Control Valve- That is controlled by the PCM to fine tune and compensate for different conditions. FITV stands for Fast Idle Thermal Valve- It uses a thermal wax plunger thing that open and closes the valve with the coolant temperature. It helps the motor warm up faster.

aasaa666

Anyway...im confused by the topic title and this picture.

mikep_95133

I updated the pic with a yellow circle. Make more sense now?

Mike

mikep_95133

Does it use PCM or do you mean PWM? Is there a thread somewhere that dives into the function of this valve and the PWM side of it?

Mike

aasaa666

Dont know what A PWM means. when I use PCM it may also be refered to as engine control module or ECM. Im not sure about extra info, you may want to google or check the FAQ section. It just brings in extra air and raises the RPM. Some may even consider it a defroster because coolant passes through it and at the same time heating up the throttle body and freeing the throttle plate. thats all I know.

mikep_95133

I see what you mean now. I think that the IACV is controlled by just the 12 volts being on or off, nothing fancier than that.

PWM = Pulse Width Modulation
PCM = Pulse Control Modulation


Mike

mikep_95133

This morning the car sat all night, so it was stone cold. When I started it up, the rpm ramped up slowly to a 1600 rpm idle over about 5 seconds. It used to jump up to 1600 rpm. I just sat there and watched the idle rpm instead of driving around. In just a few minutes the rpm had crept down to 600rpm. Before this adjustment of the FITV the idle would surge for something like 15 minutes before it smoothed out at 600rpm.

Mike

mikep_95133

It's been a couple of days since the FITV adjustments. The car run great the many times I've had to start it up from cold or cooled down. As the temperature needle climbs up the rpm slowly goes down. Not a bit of surging! Very nice.

I'm thinking that over many years and many thermal cycles, the wax filled module in the FITV does not work as solidly as when it's new. So adjusting it when it starts to act up at least gets more use out of it before a new one is required.

Mike

mikep_95133

All of these past posts were in relatively warm weather. Once the weather got cold this winter the surging came back. I had previously backed off the FITV adjustment 1 full turn from tight. And that worked. But the last time I owned the car I had reduced it to 1/4 turn back off and it would only surge sometimes. Not sure what happened. The FITV was new-ish.

Mike