AtoZ

This the second time I am having to write this thread. As I was writing this thread in the Honda-Tech 1990-2000 forum, I was literally prevented from posting the thread. But I have a good memory, so it is nothing more than a delay in getting it posted. So, here is the issue:

I assume that many people who visit the www.Honda-Tech.com Internet site, and the various board members know, that some Honda-Tech members advise, and give instructions on how to alter, modify, adjust, whatever adjectives describe the screwing down or turning in of the Fast Idle Thermo Valve (fitv) white plastic valve, located on the firewall side of the throttle body. My understanding is that the purpose for doing that is to prevent unwanted air from entering the engine when the engine has reached full operating temperature, ie., warmed up, if the white plastic valve has become loose, and is not providing a good seal. But I have also read of other issues and reasons for doing this, primarily to lower the fast idle rpm. In particular, one board member said [verbatim quote], "Where did you get the idea that I said the engine rpm would be lower on a cold start if you did this modification?" I can see why that board member took issue with that.

My understanding is that the ECU controls the idle rpm on a cold start, based on the various inputs it receives from the various sensors etc., on the engine. And based on that data, it communicates with and instructs the Idle air control valve [IACV] to allow a certain amount of air into the engine. Now, my problem is this: I noticed that the fitv has a long straight shaft of a plunger in it and that it that becomes extended, to push up against the white plastic piece that seals off the unwanted incoming air into the fitv when the engine has reached full operating temperature, ie., warmed up. Several H-T board members advise owners of Honda vehicles with the fitv, to screw down or turn in that white plastic part in the fitv by placing a wide tip screwdriver type of tool in the notched area on the top of it. Well, since engineers designed the inner working of these parts, and since springs and plungers of this type are under a certain tension, could it be that the factory setting should not be tampered with, as both the Helms Service Manual and the Honda Factory Service Manual both advise not to do. I have a special hand held gage that is for measuring tension. It is a Sherr-Tumico branded tool. This entire tension thing is what it is designed to check and adjust. So, could it be that when that plunger is not allowed to go the its full length, i.e., its factory setting, that its design tension might be compromised and actually cause sealing problems for the fitv? Causing too little or too much tension? Or, could it be that you guys here on H-T that advise altering the factory setting of the fitv, because you have discovered a design flaw and the fitv is better adjusted as per H-T advice -- Prove it !

Well, I am considering purchasing a new fitv, and so, I would like to know if you had a brand new fitv would you turn that white plastic part in all the way "before" you installed in on the throttle body.

GhostAccord

I would say No to adjusting the new FITV it's not a performance mod or adjustment to do for no reason. Adjustment of the FITV plunger is the last thing you want to do. I have never agreed with adjusting this plunger unless you knew that it had moved from it's factory setting. Same as the idle adjustment screw, it's covered in silicon from the factory for a reason. 9 times out of 10 there is another reason for an idle issue that should be looked at before making adjustments to factory set items.

Now if you are having problems with an older FITV and you know that it is in fact the FITV that is the cause of the problem. Then I would suggest adjusting the plunger vs buying a new one. My suggestion was always to remove it if it's causing you trouble. It's not an essential part of the PGM-FI system. The ECU has no control over it at all. It's controlled by the temperature of the engines coolant. If you can hold your foot on the accelerator for 2 minutes your car will be just as warm as with the FITV working. On real cold days, After the valves stopped tapping, I always held my car @ 2500-3000rpm for 2 minutes and she'd be blowing warm enough air to defog the windshield. That's all I needed to get rolling.

Your statement about the service manual telling techs not to make adjustments is the same as it saying that you are not to replace the TPS or adjust the throttle stop screw. In the case of the TPS you are told to replace the entire throttle body. Why is that? I have replaced 5-6 TPS sensors with absolutely no issues. So are you going to buy & replace the entire throttle body just because the manual told you too. When there is an easier and just as accurate way to do it?

AtoZ

Ghost, I thought that you guys turned in that white plastic part of the fitv, even if there were no idle problems, just as a preventative step. Ok, I'll leave it alone if I get a new one.

Btw, is there a spring on that long stem plunger shaft, I don't remember if there was or not?

My fitv was really a mess. The long plunger stem inside of the fitv bore was off at an angle, not coming out straight. I went thru the usual steps of cleaning the iacv & fitv, and adjusting the fitv. I had a little suction if I left my finger tip on the lower TB port there for an extended period of time. I also found that my fitv brass plunger tip was not sealing very well on that white plastic part; and I think it had an internal leak, involving the triple O rings. So, I set out to make it all better. I tried to remove the burrs and nicks in the plastic part and get it flatter and smoother where it is supposed to seal, but I was only able to do so much with the tools I had access to. The fitv is sucking much more air now. I convinced that plunger/shaft is off at an angle again. I wonder what causes that to happen? Bottom line the fitv is just too far gone in too many ways to fix. Since I have taken the fitv apart, I have often wondered why the designers of that part chose to use brass on plastic as the seal. I think some rubber would have made a better seal.

QUOTE: "Same as the idle adjustment screw, it's covered in silicon from the factory for a reason. 9 times out of 10 there is another reason for an idle issue that should be looked at before making adjustments to factory set items." END QUOTE

Now there is a very good point, because it only compounds the problem and then you have to figure out where the idle screw was after you mess with it. But I see where that advice is often given as a first step [but, obviously not by you].

QUOTE: "Now if you are having problems with an older FITV and you know that it is in fact the FITV that is the cause of the problem. Then I would suggest adjusting the plunger vs buying a new one." END QUOTE

Do you literally mean the long stem plunger shaft, or do you mean screwing down that white plastic part with the two notches in the outer end of it, as a means of adjusting the plunger indirectly? Because, I never attempted to adjust the plunger, all I could do was to pull it back in a straight line from being off at an angle. But I don't see anywhere that the shaft itself can be fixed. Right at the bottom where it disappears, it has a little circlip of sorts on it. I think that area is where my problem developed and something is off at that spot.

QUOTE: "Your statement about the service manual telling techs not to make adjustments is the same as it saying that you are not to replace the TPS or adjust the throttle stop screw. In the case of the TPS you are told to replace the entire throttle body. Why is that? I have replaced 5-6 TPS sensors with absolutely no issues. So are you going to buy & replace the entire throttle body just because the manual told you too. When there is an easier and just as accurate way to do it?" END QUOTE

Another good point. I agree completely, and have followed your thread about that whole TB and TPS thing too, and modified and adjusted my TPS.

One last question: When you are driving one of these 5th Gen Honda Accords down the road, does the iacv and fitv cease to function if they are functioning properly ... meaning are they strictly idle valves only and cease to function once throttle is applied? That seems to be how my engine functions, not having any drivability issues, only idle issues when the car is warm.

TouringAccord

cut it out
the only person who prevented this from posting the first time was yourself!
no one, but yourself, is able to see what you are typing before it's posted. only once it's posted are we able to see it and edit it.

AtoZ

TOURINGACCORD:

Ok, if you say so, that's good to know. But it sure didnt feel like that when it happened ... and I suppose I read too many threads from people on the net and talk to lawyers that tell me that eavesdropping can is is going on at an unbelievable level. The things I am told that is being done thru technology is just apalling, to say the least.

Your misunderstanding what I meant. I'm not claiming that H-T is doing it, I was claiming that it seemed like that. Ok, its like this. I was knocked off a site a few years back and had to restart my computer. I called AOL. AOL told me that websites have the power to do that. I dont know why that happens, I only know that it does.