how long for ecu to learn?

[zen]

look.took peoples advice that -10 iacv is compatable with -20 iacv..(please see other postings on here of me banging my head against the wall, no sorry iacv valve issues..)

but now (remember iacv wound itself shut when tried before)i have no idle control at all!

it stays at min tickover (500rpm when warm, stalls when cold,)
it has no high speed when cold idle at all..ie it don't work..

now people said the ecu may take awhile to readjust itself.(why??how does it even know i changed the iacv???)if this is so how bloody long???its had 30 mins or so of driving, 6 start stop engine times...

help, i know the -10 iacv is good, so why not work,surley the ecu learns quick??

 

[zen]

i dont have to disconect the ecu from battery to reset it, to allow it to learn again do i??(just a thought)

 

[sc-driver]

Back when I was messing with my air box and mass air flow sensor, the ecu wouldn't sense that there was a change in the volume of air and the exhaust would sound very strange. Sounded like a truck.

It didn't matter how many times or for how long I disconnected the battery terminals, it always sounded strange.

So I drove for about 30-45 mins of HARD driving through the canyons and a 15 min drive on the freeway back home and the ecu learned the correct volume of air. I know this because when i arrived home, it sounded like it used to and had a slight better pick up.

 

[v8soarer_1991]

it takes about 20mins of driving to learn the engine side of things.

the computer stores the last 10 - 12 stop starts.

so within the 10 - 12 starts the computer averages the shifting pattern to suit.

so if you drove like a granny for a few days then you want to put the foot down its a little sluggish for the first 2 - 3 times than after that you start to notice a change, quicker drop back, harsher shifting.

"tip"

before you go on the dyno go for a fang around the block before you place the car on the dyno.

 

[lexdud]

The first day I installed a new ECU it idled very low (3-400 RPM). Drove it for about 3 miles and then garaged it. The next day it drove a little better, drove it about 5 miles. By the third day it was purrring like a kitten.

 

[zen]

no..i give up..not compatable...95 iacv not the same electrically as 91iacv..(but i dont see why, unless one of the poles is reversed)

now had 4 hrs of hard/soft/satart/stop driving...no f***ing tick over..no cold start high idle...

i will not pay what toyota want for a new one..i can buy a complete m112 setup for the same!!


so gonna make my own iacv, unless someone can tell me why the suposidly compatable valve ain't working..(as stated it is a good one)now to learn about stepper motor controllers and pic progrramming so can make my own idle control computer..atleast then i (and not the toyota ecu) can set the idle values ...can't be that hard,after all its only a unipole stepper motor afterall..

 

[zen]

ok..more info...definatly not compatable,ecu will not drive the 91 iacv..they are different voltage stepper motors...

 

[Zuffen]

Whilst the '95 IACV isn't rebuildable, have you trued pulling it apart.

Toyota put it together so why not try pulling it apart? Worst you can do is throw away a non-functioning part and the best you can do is find out what the problem is and get it working. Don't forget photos as you go.

Another option is if it's seized; why not soak it in machine oil for a day or so?

 

[stevechumo]

Try this link: the friend in Aussie has a tutorial to rebuild the IAC: http://www.planetsoarer.com/IAC/iac.htm

 

[zen]

unfortunatly that artical is for the 91 iacv..i have a faulty 95...

yes next step is to attack it and try to open it up, or drill hole in it and dump in diesel/wd40 for a while!!

but first to get some idle back...have now found 2 simple circuirts to manually control the valve (ie my 91 iacv that the 95 ecu wont drive) so can then atleast have an idle, and with a bit of thinking will get it to monitor rpm and be setable to where i like..ie 750rpm hot.

 

[Zuffen]

What voltage does the '91 unit run and what is the voltage of the '95 unit.

It should be simple enough to drop (or increase) the voltage as needed.

Seems a whole lot simple than building a controller to run the '91 unit.

 

[Cobber]

I have come accross this before there does seem to be a difference some times but I am 99% sure it is just a couple of the poles reversed. There are 125 steps and the power will be 12v.


Mine needed to go 1,2,4,3 to make it work.

try this

 

[zen]

well..see whats that info for??thats for my 91 ..now i thought it was a different voltage device due to its impedance off 22ohm compared to 44 off my 95 iacv..

i assumed that to be the reason my 91 would not work in the car ,but would on the test bench...

however...it appears to have been that star washer that sits under the bottom bearing in the motor.stripped it again,reversed washer..now works..dooh!

so contra to what i said 91 iacv works in 95 car...

i am in the middle of stripping/repairing the 95 iacv though..so far without busting it i have the motor seperated from valve assembly. hopefully tomorrow i will work out how to strip down the motor..(need a superglue type adhesive "melter")as its held together by glue..if i cant seperate then will soak motor unit in wd40 over night..
construction of 95 valve is not as good as 91 valve,plastic plunger, crap screw thread for it run on etc..

oh ecu learn't settings (now iacv moves) instantly

 

[zen]

barstard!!!

the 91 iacv has gone faulty..stuck fully open...oh well time to put back in the "rebuilt" 95 one and see what happens...

can see me buying a new one !