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OK so I am a new subscriber to Eric’s video’s. Love them, very informative. I like to do things myself and save $$. My 96 Civic EX had a rad leak months back and overheated really bad. I bought a new rad and installed it. No overheating now. I have heat when I want it too. MY idle jumps up and down regularly between 900 and 1800 rpm. I bought a no spill funel and burped the radiator as per Eric’s instructions and lots of bubbles came out. The only thing I didn’t do was open the bleeder valve because I cannot find it. All the videos online of civics and other honda’s are of engines which have the throttle body facing to the passenger side. My car has the throttle body facing upwards. I checked inside the distributor cap for oil, nothing. I cleaned the throttle body, I checked the coolant for oil, nothing. I checked the oil for coolant, nothing. I did a cylinder power test and all good. I need to know where the coolant bleeder valve is so I can purge the air and stop the bouncing idle. Also I am pretty sure the iacv and fast idle valve are under the air filter housing which sits on top of the throttle body but I can’t figure out how to take of that air filter housing to access it all. Anyone have any tips? Thanks.
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Don’t even worry about the bleeder valve.Its purpose is
to fill the system faster not burp air.if you feel there is still
air in the system. just do the procedure per the video.As stated the bleeder valve is NOT important to the procedure, it’s only there to make filling the system easier. Every other part of the procedure in the video IS important so you need to follow EVERY step to properly purge the air.
Not sure exactly how to remove your air filter housing. But you are correct about the location of the intake air control valve. It’s located at the rear of the intake manifold between the manifold and the firewall. If’s it like an Accord the working room is tight. Probably need a 1/4″ drive ratchet with 12mm socket in order to remove and clean the iacv. If you remove the two coolant lines on the iacv you will need to purge the coolant system again.
Thanks for all your responses. I repeated the cooling system purge proceure and let the car iddle for an hour with the funel on. No change in the fluctuating idle though. What else can it be? Thermostat? I have heat though and the car doesn’t overheat. I’m stuck…
If you followed Eric’s video and you are sure that all the air in the coolant is purged I would check that off the list. Probably not tstat issue as well. Try this, when the car is having the fluctuating idle take the handle of a screwdirver and tap on the IACV. If the idle stopped flucuating then IACV is the culprit. You might also try to remove the IACV and clean. The screen on one of the ports will get blocked, so I have used brake cleaner or throttle body cleaner in the past. Eric usually says replace and don’t bother to clean. You might want to check the fast idle valve. After you remove the cover there is a screw that you can turn clockwise that sometimes corrects the idle issue. Eric has some great videos that address both of the above mentioned items. Good luck and keep us posted on what you find.
Thanks, yeah I want to do the IACV and fast idle valve but I cannot figure out how to get the air filter housing off. I can’t find bolts or screws holding it on. Does anyone have experience with this engine set up?
See if this drawing helps for the removal of your air cleaner housing. Appears item 5 on the drawing must be removed. But first remove top panel on the housing and the flex. hose. Hope this helps.
If your civic is a manual the iacv is the small black cylinder like thing on the rear of the throttle body. If its an automatic it is green colored on the bottom of the throttle body. I took the throttle body off my 00 civic ex automatic and it really wasnt that dirty. I took the iacv off there was like 4 little bolts and there is no screen in the iacv in mine and it really wasnt that dirty in there I cleaned it out a bit but it did not help my idle problem.
Idle problems are caused by mixture problems, usually too much air. The most common cause of this is vacuum leaks so be sure to check for those. Also I’ve seen some Honda PCV valves fall apart internally, to check for this (please don’t just replace the valve, Honda valves are SOOO much better than the aftermarket ones) pinch the line going to the PCV valve while the engine is running, if the idle smooths out replace the PCV valve with a Honda unit. Lastly here’s my ‘idle speech’ with some other useful information that might help you.
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.
The Bleeding a Cooling System Video
The video response to the Honda Idle video
http://www.youtube.com/watch?v=AMjQry8mz-E&feature=watch_response
Lastly 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.
Thanks everyone for your advice and thank to Eric! I did the cooling system air purge procedure yet again and no change. Funny thing is, it idled and ran great up until I replaced the rad due to the overheating. It has to be air in the cooling system but I can’t seem to fix it. I took the air filter housing off the throttle body but was not sure what the iacv or fiv looked like. I’ve only seen videos of the sideways facing throttle body engine design. Frustrating… I might just have to get it looked at by a mechanic. On the up side I aimed my headlights with the screw driver lol.
So when I had the air filter housing off, I think it was the iacv but not sure, I banged it with a screw driver handle and nothing. I have no idea which one was the fiv. I just went to pinch off the pcv valve only to find I have no idea where it is. Seems I am not very good with this engine design. My other car is an 04 SiR and I love how the intake manifold, throttle body, pcv valve are right in front of my face when I open the hood.
Did you watch the video in the ‘idle speech’ posting talking about how the IAC gets it’s information and WHY air in the cooling system would cause a fluctuating idle? If not I would suggest that you do. The fact that your idle started having problems after you did the radiator SCREAMS air in the cooling system to me. Make sure that you’re doing the procedure correctly, just letting the engine run for an hour with the radiator cap off isn’t going to cut it, you need to follow ALL the steps with the exception of the bleeder valve in order to be successful in purging the air from the cooling system.
Thanks, yes I watched both vids again and I understand a bit better. I did the cooling system air purge again and now the idle no longer bounces. It now sits at 1500 and is mostly stable but with fluctuations intermittently. My check engine light came on and the car shook violently when giving a little gas. Runs ok when giving lots of gas or idle. I checked and one of the sensor plugs was loose from when I took the air filter housing off to tap what I thought was the iacv. This sensor plugs into that piece. I reset the engine check light by pulling out the radio fuse under the hood for a minute. The car then drove great and a little while later the light came back on and the car shudders hard when driving and trying to give a little gas again. Did I damage the sensor or whatever that piece is it is attached to? It is on the throttle body facing forward. tps?
So after some contemplating and research, I’m quite certain that what I tapped on was not the iacv but the tps. I might have damaged it but the thing that gets me is why does it drive fine after I reset the check engine light for an hour. Then when I shut it off for a bit and start it back up, the light and shuddering are back? If the tps is damaged, wouldnt it still shudder even after resetting the check engine light?
I just reset it and it drives fine… Its great for about and hour of driving time then the light comes on and it shudders and shakes again when giving a bit of gas. Then I reset check engine light and it’s fine again.
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