I just read all the posts I could find on the FITV valve because I was having the rev up then down then up then down when cold as described in most of those posts. I have a '93 4cyl Accord. I went in and tightened that white plastic thing all the way and that immediately stopped the revving.

My Problem is that when I turn the car on in the morning it does not have any fast idle at all. It immediately goes down to 700-900rpm right off the bat. No fast idle at all. I also removed the ECU fuse for a minute to reset the ECU. What I am wondering is if that plastic piece is really supposed to be screwed all the way in until tight or is there something else I should check? I really didn't understand the blocking off a hole to see if there is a vacuum parts of the posts.

Any ideas????

 

Depending on the outside temperature, the fast idle might be at 900 rpms. When the car is at normal operating temperature, is the idle at 750 +/- 50?

There are two holes ouside of the throttle plate that the FITV and IAC allow air to bypass a closed throttle plate. You have to remove the intake hose to the throttle body to see the holes. When the engine is cold, the FITV and IAC both allow air to flow into the engine. Once the engine is at operating temperature, the IAC should only allow air to get into the engine. The FITV hole will have vacuum only when engine is cold. When warm, there might be a slight vacuum on the FITV hole. The IAC will always have vacuum.

 

You screwed it too far, the Fast Idle Thermo Valve is what controls that fast idle that you no longer have. There is a wax pellet inside, this pellet heats up via the antifreeze that flows through the FITV component hense the two small coolant hoses going to it (sometimes one if its integrated with the intake manifold). This was pellet expands as it gets warmer, pushing on the valve that you adjusted by hand until it closes off all of the extra air flow bypassing the closed throttle plate, this is refered to as a controlled vacuum leak.

The FITV is adjustable, but it is not supposed to be adjusted when it gets old, like what you did and thousands of other Honda owners. It is supposed to be replaced, BUT this is an acceptable temperary fix, readjust it back down a little, the wax pellet should close it the rest of the way, it was just not doing its job well when you were experiencing the cold surge.

Did you understand the covering of the holes at the enterence of the throttlebody from the last post. Its you troubleshooting technique to test for this vacuum leak.

Sometimes when there is a coolant leak and the radiator is not full, the FITV will not get coolant so problems will arise from lack of coolant in the FITV and even worse is when the coolant lines get clogged with crude stopping the flow of coolant to the FITV.

 

I would probably say, no. I need to see if I can find out where these two holes are. For starters I am going to loosen the valve a little for the time being and then try to see where those holes are and then go through the diagnosis procedure. The car has 242,400 miles on it so I would bet the valve is worn out, but maybe the adjustment may give me some more time.

 

Do the valve adjustment cold, full cold. You should not need to loosen them, you should need to tighten them but whech ever way they need to go, you need to use the correct feeler gauge for the intake and the correct gauge for the exhaust. And with the cams set up the correct way too.

http://www.c-speedracing.com/howto/v...alveadjust.php

Will this help any.

 

aaah, wrong valve........ I am still working through the FITV valve, not the intake/exhaust valves. (I know how to adjust them). I still need help on the FITV though. It sounds like you help so many people here you might have two of us needy for information people crossed up.

 

SORRY, not people crossed up, just valves. Let the engine fully warm up, really warm, even go for a drive. Pull the cover and adjust it till it starts to leak air and then close it again + a little more turn.

There is a wax pellet inside that expands with hot coolant and it pushed on the FITV to close it and prevent an internal vacuum leak. Let me know if this does not help or if you may have a different problem.

The FITV is not really supposed to be adjusted, thats for the original factory setting, it is supposed to be changed, so lets call this a temp fix.

 

If that will fix it so it is bearable it should hold off replacing the valve for a little longer. I actually fully tightened it and had the problem explained above. I then loosened it two full turns and the surging has returned. I have tightened it back 1/2 turn so I am now 1 1/2 out with the problem still there. I plan on tightening it as you have recommended wich might just be 1/2 turn tighter from the looks of things. I'll keep you up to date on this.

I might end up just replacing the valve. Majestic Honda has it for about $54.00........ I still have to call around though.

 

I ordered a new valve from Honda. It looks to me to be simply a unbolt then rebolt and transfer the two hoses procedure. Is that all it takes to replace the valve? Since it gets pretty cold here at night I need this valve working. Didn't want to have a problem when the wife uses the car in the winter so I figured replacing it is the best idea.

 

Is that all it takes??