Any way to adjust IAC/cold idle



  • Yo, thought Id clog up the board with another question, anyone know of a way to adjust how high the revs go when the engines cold, id like it to jump to 1000 rather than 1500, seems a bit unnecessary to rev so high, and its very noisy at 5am!

    Oh yeah, and whats the point of the idle adjuster screw when you can just do it on the throttle stop?

    Thanks, James



  • Would love to have jsut 1500 tbh, Mine hits 2k-2.5k on cold mornings mine does idle at just under 1k tho.

    So would like to know as well.



  • glad im not alone, I personally dont really understand the need for it at all, most cars dont have an increased idle, so why does ours need one? read about people removing the IAC connector so it doesnt work at all, but also read some people have had the CEL come on when doing that, anyone got any idea how the thing works or a picture of it removed from throttle body, might be able to put in an extra gasket, then it wouldnt push so far onto whatever its opening (im guessing its the butterfly valve or similar)



  • just spent this time searching and reading the manual, theres some intriquing stuff in there, anyway, i have an idea, 2 actually, so im going to try them out and ill let you know if either one works



  • Please do bud!..

    I'm a little busy work other things to read car manuals right now :(



  • but not play on forums? SHAME ON YOU! :)



  • not had a chance yet as its dark 2 hours after i get home which is about as long as it takes for the engine to cool down, and my fiancee is currently in hospital with apendcitusiusiness or however the hell you spell it, stupid medical words, why not just call it "inside out and knotted appendix syndrome" ? So this will have to wait til the weekend, the ideas i had are, checking resistance when the engine is cold, the IAC is 10-12ohms at 20degrees centigrade, so theoretically if you just disconnected the IAC and put in a 10ohm resistor the IAC shouldnt function but also shouldnt give any ECU errors, what id like to do is have it so it comes on but is limited to the 1000rpm region (obviously your already there so you may aswell cut the iac out all together) but have it so that its at 1000rpm when its cold but goes down to normal idle (700rpm) when warmed up, this will take a bit of effort as my electronics qualification knowledge expired 10 years ago, so im currently trying to find answers to jog my memory.

    I had thought I could just put in a resistor in parallel, since electricity is said to flow the least resistive path, which would mean if the iac is 20ohm resistance when cold (i dont know i havent checked yet) then itd run on the 15ohm resistor i wanted to put in, then when the iac became lower resistance than the 15ohm resistor itd switch to running from the iac input, however resistors in parallel doesnt quite work like that, stupid things, basically it works like this R1 x R2 / (R1+R2) so if you have 10ohm as R1 (this would be the IAC unit at 20degC) x 20ohm R2 / R1(10) + R2 (20) [TTL= 30] you get 6.6, so thats totally fckin useless. You know whats really odd though, is if you go to the extreme and have 10 and 1000ohm resistors then you get 9.90ohms (10x1000=10,000/[10+1000=1010]=9.90 someone please explain how in the world that makes any sense!

    So it looks like itll be a case of figuring out some kind of pcb with transistors and stuff, of which if I can get to work, im going to patent, then sell for 1 meeeeelion dollars! or £10 at the current market state.

    The other method was to adjust the AAS, since mine is set to idle at 700 using the stop screw, with the tps reset to accept that position, so the AAS which is actually an air mixture screw essentially, might change the flow of air through the iac bypass, which should inturn sort out the high idle, of which i cannot charge people for this concept, however, they better appreciate the time spent thinking about it because no doubt in a short whole DJ will be in to tell me that it wont work :(



  • so how did it go. you have a chance to try it out??

    hope the girlfriends ok?



  • @3eb6e0751e=Jesta:

    Yo, thought Id clog up the board with another question, anyone know of a way to adjust how high the revs go when the engines cold, id like it to jump to 1000 rather than 1500, seems a bit unnecessary to rev so high, and its very noisy at 5am!

    Oh yeah, and whats the point of the idle adjuster screw when you can just do it on the throttle stop?

    Thanks, James

    Umm, that's waaaay too high for a start off anyway, they should idle at around 500-800.



  • Eddy> yeah had a mess about, its not do able. Ive dropped about 100rpm off the cold start idle by winding the AAS 1/4 turn out from seated, the BAC valve/IAC must be a motor, which I didnt realise, I measured it at 3degC and it had no connectivity, so it must be a motor as I then tried to start the car without plugging it in, and the car refused to start, plugged it in, car started straight away. So the idle speed appears to be controlled by the ECU unit which detects the temperature from the engine temp sensor and then uses that to calculate how much to open the BAC valve until its desired idle speed is reached, the BAC also appears to be what is triggered to open to increase revs when you put extra load on the system, such as lights, heaters etc, gonna roll some cigarettes and stare at the wiring diagram, try to figure it out from that.

    Nightstalker> Nope, theyre designed to increase the revs when they are cold started to help bring the engine upto temperature quicker, its also easier going on the cams, but thats another story, read up on kawasaki's suicide choke. Anyway, if yours isnt doing that then your BAC unit may be bust or someones disconnected it.



  • Ah, read wrong, I thought you were on about idle not start up.



  • this is unrelated to anybodies posts that proceed this one, but just wanted to say this before someone blames me for giving them the wrong info

    It should be noted that anything I write in this thread are my own ideas, observations, assumptions or conclusions, and there is a distinct chance I could be very wrong, so please dont start hacking up stuff because you read something ive posted in this thread, if you want to try and make a work around for this issue then please feel free and post up your own experiences and info in this thread, however, if you read something here and take it for fact and then act on that, then your an idiot.



  • @6aa83cfdda=nightstalker:

    Ah, read wrong, I thought you were on about idle not start up.

    the title says cold idle :roll:



  • @8c89ee130c=Jesta:

    @8c89ee130c=nightstalker:

    Ah, read wrong, I thought you were on about idle not start up.

    the title says cold idle :roll:

    I'm drunk lol :lol:



  • @59a24ab655=nightstalker:

    I'm drunk lol :lol:

    ok your excussed then :)


Log in to reply
 

Looks like your connection to UK-MX3.COM was lost, please wait while we try to reconnect.