Idle problem write up
A while back, my civic dx (d15b7) was having an idling problem. The idle would surge up and down sometimes, and other times it would be ok.
This went on for a month, and I finally got fed up with it. I began researching it on the Internet to see how to fix it.
The fist thing I tried was cleaning the mesh on the Idle Air Control Valve, but that didn’t help. Then I was told, it might be my TPS (Throttle Position Sensor), but I wanted to try out one more thing, before I went and bought it a new sensor.
So I found out that the real problem was the Fast Idle Thermo Valve (FITV from now on). And this is where we begin. This write-up should work for b-series engines as well, not sure about the others, but I’m guessing it should work with h-series, ect…
Here is a picture of the FITV
Step1- The first thing we will do is try and determine if this is actually your problem.
We will begin by removing your intake from the throttle body. Now you should see two holes on the inside of the throttle body, we will be working with the bottom one. Here is a picture of the actual throttle body (it is not of my car, as I did this fix last week, I found this picture on the internet, but it should do fine.)
Once you have done this start your car and let it warm up. When it is warm enough to where it would be good to drive, put your finger on the FITV hole in the Throttle body, as seen in the picture. If it still has suction then that means, the FITV is the source of your idling problem. If not, then try cleaning the mesh on your idle air control valve, replace the TPS, or check for a vacuum leak. But if this is your problem read on! J
Step 2- Now we are ready to take the actual FITV off. The first thing you want to do is take the hose closest to the firewall off. Take the clamp off using a pair of pliers, or in my case, just your fingers. Some coolant will come out, but that’s ok, just put the hose to the side for now. Don’t take the other hose off yet, because it is much easier to get off, once you take off the actual FITV.
Step 3- The next step is to take the three 10 mm bolts off from under the FITV. These are in a really tight spot and are a pain to unscrew, but just be patient, because hearing a smooth idling car in the end is very worth it. Here is a picture showing where the screws are located. I couldn't find a bottom view of the FITV, but this should give a good idea of where the screws are.
Once you have taken off the three bolts off, you can take the other hose off in the same way as the first. The FITV will have some coolant left in it, so be careful not to get yourself wet as I did lol. After the hose is off, bring the FITV to the side.
Step 4- Look at the front of the FITV which should look like this.
Take the two screws that you see off along with the plate. Now you should see the plastic screw that we have been hunting for. Here’s the pic.
Now what you need to do now is tighten that screw until it stops. Don’t tighten it too much, just enough to where it is snug with the lower part. This plastic screw, limits how far the piston inside can travel. This is done so the car can idle higher, in turn warming up faster.
Step 5- Congratulations, you have just fixed your FITV. All you do now is put everything back together in reverse order. Be sure to clamp everything down perfect, and tighten the bolts down pretty well. That should do it.
If there are any questions, feel free to ask.
Leave me some feedback on what you thought was good. And please tell me if I have stated anything wrong.
Hope this helps.
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Originally Posted by jdmhondager
