1999 honda accord v6...heres the deal...ive read everything i can find but still cant get straight on my problem...idle surges between 1500-1800 slow at start...then changes after about 15-30 seconds of running to a fast up and down surge...
theres no bleeder for the cooling system located near thermostat houseing or anywhere else for that matter,i searched everywhere...
so i moved on to disconnecting the plug to the iac,no change,idle still pulses very fast still at 1500 rpm...i removed the air intake and put my 2 fingers over the lower hole to iac and when plugged drops down too a low idle...so obviously the iac is stuck open?...i would remove the iac to clean it but without finding a bleeder screw,i am wondering how to bleed it?...also wondering if i can jump the iac selenoid at the plug to test if its closeing opening as it should?...also if anyone has a base reading at the iac so i can test resistance at the plug...
this started happening after i removed and cleaned the dirty egr vlave...i did a spray test on the egr and other vaccum lines with ether and no fluctuations anywhere...p0505 code now...where as before cleaning the egr and reinstalling i had a bad egr code...now gone,but directly after reinstal of egr,the surge started....all plugs and wireing look clean and all vaccum lines are tight...any sugestions...i know people are going to say replace the iac...but like a said,bleeding procedure?pics on bleeder location? and like to rule out falty wireing,and test incoming wires...also set idle procedure was never clarified if it works on v6,everythings about 4 cyl...wouldnt go down to 550 anyways unless i block the iac....dont have much money so buying a books outta the question...thanx for any help anyone gives me in advance...love this forum and i solve alot of problems from researching here

 

I'm not completely sure, but I think the V6 didn't have a bleeder screw for coolant. That's becuase the location & elevation of the thermostat doesn't cause air to hang out there. It gets swept over to the radiator where you can let it out through the radiator cap.

When you unplug the wire from the IACV, it's SUPPOSED to close. That's the idea behind the base idle - IACV is closed & the RPM is adjusted to 550. I know there hasn't been anybody truly verified that it's the same procedure for a V6 (I've never owned a Honda V6).

So with the IACV unplugged, the idle is still high AND SURGING? And then you can plug the port & the idle drops down low? That really does sound like the IACV is stuck open.

If the idle stayed high when you plugged the port, I would've suggested you continue looking for vacuum leaks. However, that's still possible so look closely at the air passageways to/from the IACV for anything like bad gaskets. Maybe check the gasket between TB & intake manifold?

So I'd remove the IACV to clean it. It seems that Honda IACVs don't often fail, so cleaning is the first thing to try. But yours does sound like maybe you need a new IACV.

 

yes that is true...ive read alot of your sugestions jim and i have also only owned 4 cyl till this one so its sort of new to me...aic stuck is what i figured but i was wondering if it is stuck like this untill actived by an electrical signal which tells it to do what it needs to do...like i said this is somthing that started directly after messing with the egr sensor...so wasnt sure if maybe a backload from reclipping it back in could have messed up the ecu/ecm and be causeing it to malfuction or send the improper load to operate it corectly...ive done extensive vaccum checks and find nothing loose,cracked,or hissing...no high idles with a spray test anywhere...would hate to buy an aic to find out it was a bad conection from the ecu/ecm....trying to cover all the basis before buying parts...didnt want to hot wire test the aic either unless i knew it wouldnt short during a hot wire test....looked for voltage reading/ratings for the aicplug,but finding nothing anywhere O.o

 

i did a voltage test on the aic plug and get this...
black wire=ground...
yellow wire=positive and getting 14.36 volts fluctuating at the .30 too .40 area
blue wire=appears to be negative as well...

hits me as odd that there would be 2 grounds in one 3 point clip...can anyone verify these readings as correct operating funtions???

 

Is that back-probing the wires while they are plugged in? Engine running?

When the engine isn't running, the PCM isn't trying to "run" the IACV so the signal wire should have no signal on it. I'm not sure about this, so a wiring diagram & troubleshooting instructions from a shop manual would be very useful.

 

yes thats plugged in engine running...figured if it could handle 14 i can hot test,and got zero response from iac...im going to pull it and clean it and hopefully get it functioning correctly...i'll give you an update in a day or so...just seemed odd to me there was 2 grounding points on this plug O.o

 

ok so i cleaned the iacv and put it back in,still idle surgeing...so i went and bought a new iacv and installed it,still idle surging bouncing from 1000-3000 rpm...i had the intake off and cleaned the intake and egr tube and port,cause i figured 300k miles,prolly good to do anyways...and it was due for it,lol...so any other suggestions that would make the idle surge other then iacv...im stumped when i first start the car it is fine for all of 5 seconds before idle starts to bounce/surge...when i unplug the iacv the idle bounce/surge gets faster...heres a youtube vid of it i just made... http://www.youtube.com/watch?v=-BS8J...ature=youtu.be

 

I had an identical problem with my '99 4-cyl after cleaning the intake plenum (I had the engine apart). The only way I was able to solve was to clean the IAC and remove the idle screw, blow carb cleaner in port and blow with compressed air. Then reinstalled idle screw back, etc. Sounds line some debris from when I cleaned the intake plenum got in there.

 

it was doing it before i took off the intake and throttle body for cleaning...gave it a good soak in my parts cleaner bin and everything was spotless when reasembled...even though i know the idle adjustment screw cavity is clean,when i screw it in all the way or out all the way"without removeing it" doesnt change the idle at all whatso ever...got me still baffled...thanks for the idea though...always up for more things to try

 

It's not the cavity, it's the air duct that goes from the IAC to the screw and then from there to the plenum cavity. Can't see'em. And the symptom is you can't adjust idle with the screw. it's in Honda factory manual - idle troubleshooting guide.