1997 Honda Accord Idle Issues

I can’t say how you can get the valve off, but I would check a service manual, or maybe someone experienced with Hondas can chime in. I do know from my experience with Subarus that cleaning the Idle Air Control Valve can make a big difference in idle quality, and if cleaning doesn’t work you may have to replace it. I believe they’re usually an expensive part so I would clean it first and go from there. Sounds like you hit all the other things I would check, like bleeding cooling system, egr passages, etc. Good luck!

This is from the Chilton Online manual (there’s a link on this forum for free access):
Removal & Installation

1. Disconnect the negative battery cable.
2. Detach the wiring harness from the IAC valve.
3. Remove the two retaining bolts.
4. Remove the IAC valve and discard the old seals or gaskets.

To install:

1. Clean the gasket mating surfaces thoroughly.
2. Using new seals or gaskets, position the IAC valve on the throttle body.
3. Install and tighten the retaining bolts.
4. Connect the wiring harness to the IAC valve.
5. If raised, lower the vehicle.
6. Connect the negative battery cable.

Basically there are just two 12mm head bolts that fasten the valve to the intake. It is a little tight to get a wrench in there to break the bolts free, but it is possible. I’d try a Swivel Head Ratchet Wrench. It would give you more flexibility since it is very tight back there. There is also an idle adjustment screw on top of the throttle body located right above the intake boot. A flat blade screw driver will fit it. It usually has some sealant around the screw to prevent it from backing out, so I would spray some carb cleaner on it to help removal of the sealant. Your idle may little lower after the job is completed, you can adjust that screw to the specs: 750-850 RPM/no load. Adjust when fully warm and under no load. When you adjust some, apply a load such as the A/C and see where the idle goes.

Also one last note:You should disconnect the negative terminal for about 30 seconds to allow the ecu to relearn from scratch as it goes faster than for it to change from its existing idle. So do this after you have cleaned and reinstalled your IACV.

Before you go any farther perhaps my ‘idle speech’ will help.
By suggestion I’m going to post my idle speech along with a couple of video links that I hope will help if your having problems with your Honda’s idle. First I’ll give you the link to the Solving Honda Idle Problems video, please remember that adjusting the FITV is the LAST step in the process and you need to back it off at least 1/2 turn after it bottoms out or it will not start properly when cold.http://www.youtube.com/watch?v=L788jKEVblYThe Bleeding a Cooling System Videohttp://www.youtube.com/watch?v=zUp … =relmfuThe video response to the Honda Idle videohttp://www.youtube.com/watch?v=AMj … onseLastly here is the “Idle Speech”There are a lot of things that can contribute to an idle issue, in fact in the end it may still be there to some degree because of the nature of a 4 cylinder engine however here are some things to start with.First start with a good tune up, use NGK or Nippon Denso plugs, don’t change the wires if they are OE, if they aren’t OE you might consider NGK wires as they are very good and less expensive then OE. A quality cap and rotor should be good. A new air filter also helps.Don’t change the PCV valve, if you see an aftermarket PCV valve in there put a Honda in, believe it or not I’ve seen idle issues caused by aftermarket PCV valves, the OE’s last just about forever so you can easily justify the expense.Next a good valve adjustment, this goes a long way to smooth out the idle if done correctly, mess it up and things can get a lot worse though.While you have the valve cover off check the timing belt tension, if you feel a lot of slack this can cause the cam to ‘chunk’ as it spins causing a rough idle. If you think the belt has been on there for some time then you might consider changing it and resetting the tension properly, if it’s not ready for replacement you can reset the tension to take up the slack.DO NOT adjust the idle screw under any circumstances, it is set at the factory and that is the reason it was sealed in the first place. If you find that the seal has been broken and you have a low idle and you have done all of the above then you might turn the screw out a little to see if that helps the idle but only enough to try and bring it back to where it was before it was adjusted in the first place.Last clean the screen in the Idle Air Control valve, this can get clogged up with carbon over time and cause the flow through it to be restricted which can cause idle issues.If you still have a ‘rough’ idle after all of this THEN look to the engine mounts as you want to be sure the engine is running correctly before you go for those as the one in the back is a real pain to replace.I hope this info is helpful as I get a TON of questions about Honda idle problems, thanks for reading.

Do you have a coolant thermostat on your vehicle? Also, your coolant temperature sensor is working correctly? Your engine is not running colder than the normal operating temperature, right?

Yes. When a coolant temperature sensor is broken, the ECU will consider the high resistance as a negative temperature. This will make the ECU increase the RPM to warm the engine up faster.