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ENG: Cleaning out IAC Valve

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    ENG: Cleaning out IAC Valve

    12mm socket
    Can of throttle body/intake cleaner

    This is one reason why your car might be hesitating when you are first
    accelerating or when you are braking and the idles drop*you might have
    a dirty IAC valve. Its not hard to clean yourself, I rate it a 1 out
    of 10.

    Disclaimer: I'm not responsible for any damages or broken limbs or
    anything wrong happening to your car when you do this*this is exactly what
    I did and it worked for me. BTW, this was done on a '92 accord ex.

    On a side note, I didn't have my camera with me when I first took it
    off so I have no pics of the IAC Valve dirty on after I cleaned it but
    I'll describe it as much as possible.

    1. Disconnect the negative cable on the battery and then disconnect
    the grey plug from the IAC valve

    2. Disconnect the hose the leads form the PCV valve to the intake
    manifold to give you more room to work on.

    3. Remove the 2 12mm bolts that connect the IAC valve to the intake

    4. Disconnect the 2 small hoses that are connected to the IAC valve.
    Chances are that they haven't been taken off ever so they're going to
    be hard to remove. Keep at it though and some wiggling and prying will
    get them off. Once you take them off some coolant will leak out, just
    wipe it up with the rag and you're good to go.

    5. Now you will have the IAC valve all alone and off the car. Look at
    the back of it and you will see 2 holes, one with a screen and the
    other with out a screen*most likely they will be black covered with carbon
    deposits. This is why your car has been stuttering and running bad
    because there isn't any way air can get in to control the idle of your

    6. Grab the throttle body cleaner (I used carb cleaner because they
    have run out of throttle body cleaner but it serves the same purpose) and
    spray it on the 2 holes to clean away all the black dirt. You know
    youre done when the screen is silver (the hole on the right) and the
    diaphragm (hole on the left) is white and not black. I kept on spraying a
    bit until the liquid that was coming out of the holes looked clean and
    not dirty.

    7. Now go back to your car and clean off the area with some more
    throttle body cleaner. Voila, you're done with the cleaning.

    8. Installation is the reverse of removal. Make sure all your hoses
    are tight and to plug in the IAC valve or else you'll get a CEL.
    Connect the battery and start her up making sure the hoses aren't leaking
    and everything sounds normal.

    9. If the idle is off a bit, you could adjust by turning the idle
    adjust screw below the throttle body mine was fine so I didn't have to do

    Good luck guys, hope this helps.

    Originally posted by fizzbob7
    first off, don't be a sissy bitch.....that's what you're being
    Originally posted by ACC0RD22
    no need to get sand in your vagina over this guys.
    So. Cal OUTLAWZ

    I'm suprised nobody has jumped on this DIY.

    Combine this with ...
    1. Fuel Filter change
    2. New spark Plugs and wires
    3. Distributor cap/rotor
    4. PCV Valve
    5. EGR Ports
    6. Ignition Timing adjustment

    *You can go all out and clean the EGR and do Valve Adjustment.

    After doing this i garantee you that your car is going to be running
    like a champ. I'm in the process of doing those...i just havent finished...


      this is a good idea, i did mine awhile ago, it was packed with carbon dust.

      "You've done more threatening prescription drugs..."
      "the character of a man can be judged by how he takes his criticism"
      "Quoting yourself is like, masturbation" -Starchland


        im gonna try this soon. great diy

        Aftermath of crash.


          Great DIY, I read it today went and got a can of cleaner came home and did it. Great improvement. It idled a lil low though like you said but I fixed that. Thanx!
          1991 Accord SE


            Q: What are the torque specs on the IACV's two bolts?

            I checked the Helms manual I found online but sadly, I cannot tell if I'm missing pages or if these two bolts just aren't listed.



              WOW i just cleaned mine out it was so bad it toke 45 mins for it to run clear im not playing the thing was packed i pulled it off ad a puff of black smoke came up DAMN even though the car doesnt run im sure this would have made a difrence but of course it doesnt run lol

              Dynamic racing

              Look out for 4 point cb7 strut bars for dohc!!!

              Originally posted by deevergote
              bleh... i just put like 5 ounces of vodka in a 12 oz cup of mango iced tea...


                Originally posted by S4gunn
                Q: What are the torque specs on the IACV's two bolts?

                I checked the Helms manual I found online but sadly, I cannot tell if I'm missing pages or if these two bolts just aren't listed.

                Even though I didn't find a torque spec, I went ahead with this procedure last night and found my IACV filter completely clogged - an unsurprising situation considering my '92 has 207K miles on the odo.

                After swabbing the filter gently with lots and lots of qtips dipped in acetone, my rough-idle-when-engine's-cold issue is GONE!

                While I was at it, I ended up cleaning the throttle body but any improvement in acceleration I see is probably just wishful thinking. After all, there would have to be enough gunk buildup to interfere with the TB's butterfly operation to really inhibit the performance of this car.

                Thanks again for the write-up. Here are some suggestions I have though for any of you who have NOT done this procedure yet:

                * Consider using 100% acetone to clean the parts. Acetone aka Toluene is used by many folks as an octane booster since in its pure form it's the equivilent to 116 octane. It dissolves gunk readily (I use it regularily as a superglue remover) and evaporates quickly at room temperature. You can buy it for ~$5 at any hardware store or Wal-mart but since I didn't need to much of it, you can find a ~20oz bottle of it in Wal-mart's nail polish section for ~$1.50 listed as "professional strength nail polish remover - 100% Acetone."

                * Consider just cleaning the holes and the filter in the IACV vs. taking it apart/off the car JUST to swab the insides. For me at least, the marginal value of having the IACV completely clean didn't outweigh the inconvenience of taking the coolant hoses and electrical connections to this metal block. After all, it's the clogged filter that's choking the engine not the "disrupted flow" a little gunk on the walls of the IACVs innards that's causing the rough idle.

                * As far as how much to tighten the IACV bolts, I just tightened it enough to insure that the rubber seal around the two holes were compressed between the metal blocks.

                I was done in 15 minutes. I hope my suggestions help somebody.



                  Thanks for the tip my car runs smoother now. Got any other tips that are simple like that?


                    thanks arroz. i just did this with TB cleaner, TB cleaner'd the inside of my intake tube, and TB cleaner'd my TB. the car is soooo smooth now. it started up real quick too. kinda scary.

                    here some pics of it just to help some more:

                    my strut bar was in the way of getting my intake out so i just disconected it and used it to prop my hood up higher

                    inside the throttle body, grooooosss

                    before pics of the IAC valve, sorry didint get any after


                      Those two little hoses are a BITCH to get off..
                      To-Do List for Today
                      Be Awesome


                        well, for the heck of it, while i was working on the main relay (which to me, seems a bugger to get to), i thought i would do it too. i got it off the intake and yep, FILTHY!!! took some carb cleaner and q-tips and cleaned the heck outta it. took me longer to clean it than it did to remove and install it. the hoses were cake for me. nice being at work and got all the tools to use. heehee. but hey it's done and i'll see if it runs any better when i go to leave work. and yes, i still have the cold - no start prob. and wouldn't ya know it... it's been in the high 30's in the morning and 70's during the day. gaul dangit!! kinda wish winter would flipping get here so i can get it fixed.
                        If you're gonna go, go with a smile!
                        Current vehicles: 2006 Pacifica Touring Inferno Red (the Wife's) - 30k
                        1993 Accord EX - optima 'red top' battery, magnaflow exhaust, tinted windows - My $500 ride w/ 217k miles
                        2004 Suzuki GSXR750 - Racetech sus f/r. Dunlop Qualifiers. clear Puig DB screen. my drug - 7500 miles


                          yo just use carb cleaner or throttle body cleaner and spray it in there when u have it off. the pressure of it coming out of the can throws the crap right outa the screen


                            Will this solve the idle problem for the constant up and down rev problem?
                            My CB For Sale


                              it could, try it out, couldnt hurt. also check for vacuum leaks. have u done any other mods to it that would cause it