donbryce

I posted a thread on my A/C affecting my idle, and after cleaning the IAC and re-installing it, the engine won't idle lower than 1000. It idled perfectly before I cleaned it, except for A/C related surging. How did I mess it up?
Here's an IAC a little different than mine http://www.planetsoarer.com/IAC/iac.htm
He was able to remove guts from the lower half (non-electrical part), but mine wouldn't come out at all. I did feel the spring resisting as I pulled hard on the black plastic housing, but it wouldn't come out. Why? Here's a link to the IAC that is like mine: http://www.toyotanation.com/forum/sh...ad.php?t=86540
Also, the resistance across the terminals on mine should be 10 - 30 ohms (see the picture of the manual page in the first link, which shows the same terminals but a different resistance value for that IAC). Mine measured about 60 ohms. I read that the 'motors' on these somehow get an increased resistance and respond slowly because of this. How does this happen, as inside the black electrical part, even removed from the lower half and the rotating/bearing piece removed, it measures the same.
I sure like to know if there are any tricks to re-assembling one of these, as mine moves in and out per. spec, and the moving valve closing piece is now whistling clean....and it still doesn't idle like it did before cleaning.

GSteg

iTrader: (15)

Have you tried to disconnect the battery for at least 30 minutes to reset the ECU? It's not uncommon to idle higher than normal after cleaning the IACV, throttle body, etc. Try doing that first and maybe wait another day or two to see if the engine recognizes any change.

donbryce

Thanks, good advice. I did the entire job yesterday with battery disconnected, so maybe that would've reset it?
Anyway, I'm obsessed with this thing, so I went out today after posting, pulled it again, and re-checked my ohm measurements. Duh! I had the multimeter set on the '200' scale, and it measured, again, 60 ohms across the pins. Curious, I tried 2 resistors with the value printed on them, and got reading 3 times the value! I switched to the '2000' scale, voila, correct values. The resistance on the IAC is within tolerance, about 28 ohms.
So, back to the issue of what is wrong, I disassembled it again and still couldn't figure out how to remove the lower part internals. I even took out the little pin in the shaft, but this did nothing. Fine, I'll leave alone.
I noticed a small white dot painted on the top of the magnetized tumbler, and that if the tumbler was reassembled with the dot lined up with the small cutout on the side of the casing, there would be a tighter seal at the tip since the screw couldn't bottom out before the tip hit the sealing rim. So I turned it back counterclockwise to line this up before dropping the black case down and tightening the screws.
I noticed that the top part of the case didn't seal tight against the bottom part now, which I think might be the pressure from the curvy washer at the tumbler's top end, and having turned the tumbler 1/2 counterclockwise.
It idled about 500 - 600 on start-up, but it was fine at first yesterday too, so I'll need to do some driving to see if it's finally working right....not gonna hold my breath though.
Oh yeah, I have an EBay rebuilt one on the way just in case, which I hope I'll be selling soon.