High Idle

[4x4mike]

I've got a bit of an idle problem and was looking for some advice. All of this started during a recent trip to the desert. Whenever I would start the 4Runner after stopping, eating, peeing, taking pictures, etc. it would die. It would turn over fine and start but then die. The battery is newer and had a 12.7 charge at rest and 14.2 while the engine was running. Starter seemed fine as well. As suggested I cleaned the MAF sensor and IAC valve. The MAF sensor was dirty but not horrible. The throttle body and IAC valve were the same way. Before disassembly I labeled hoses and took my time taking everything apart and cleaning it. I put everything together and she fired up. I didn't pay too much attention to the RPMs but more to the fact the she started and stayed on. I took a drive to get some oil and came home. When I got home I noticed that the RPMs were a bit high, ~1400 RPM. Prior, when it would die the idle was about 500 RPM. I've driven about 60 miles since the disassembly and cleaning and the idle is still high. It doesn't die but never gets down to ~750RPMs, where it was before the trip.

What should I do? I've been told to pull the EFI fuse and let it reset. I could take the thing apart again but I'm not sure why becasue I don't have any extra parts left over and I can see that everything is attached as should be. I've never had any service lights turn on so it might not be that bad. Anyone run into this? Suggestions?

[paddlenbike]

Mike,
According to the 00 FSM:

"Using an ohmmeter, measure the resistance between terminal +B and other terminals (RSC, RSO).

Resistance:
Cold 17.0 – 25.0 ohms
Hot 21.5 – 29.5 ohms

If the resistance is not as specified, replace the IAC valve."

It's worth a try...

[paddlenbike]

http://www.yotatech.com/f2/backwards-hot-cold-idle-after-cleaning-iac-question-129426/

http://www.ultimateyota.com/smf/index.php?topic=2241.msg30618#msg30618

[4x4mike]

Thanks Ken. I read some one of those posts before I did the job but they make a little more sense afterwards. I'm thinking that my RTV seal maybe gumming things up. I didn't take apart any of the springs or the red screws so that must be it. I might shoot some WD-40 down there as well. I wonder if I should use the can/lighter method?

[MTL_4runner]

That is almost certainly the IAC. They are a bit of a pain to clean properly and by far the easiest (and costly) way to fix it fast is to just buy a new one (ebay usually has some good deals). If you want to clean it, then you need to be very meticulous about putting everything back together. Too much RTV in this case can definately ruin the solenoid. Also test the electrical portion as outlined above.

[4x4mike]

Well I hope the IAC isn't toast. I'm thinking I had too much rtv and it's grabbing in there. Looks like I'm going to have to take it apart sooner than I thought. Pulling the efi fuse and battery did nothing.

[MTL_4runner]

Well I hope the IAC isn't toast. I'm thinking I had too much rtv and it's grabbing in there. Looks like I'm going to have to take it apart sooner than I thought. Pulling the efi fuse and battery did nothing.


It may be too much RTV or it might just be the solenoid is just sticking by itself.

Not sure if you saw this thread or not, but it should help in your cleaning effort:
http://www.ultimateyota.com/index.php?option=com_smf&Itemid=26&topic=3148.0

[4x4mike]

Not sure if you saw this thread or not, but it should help in your cleaning effort:
http://www.ultimateyota.com/index.php?option=com_smf&Itemid=26&topic=3148.0

Thanks, I saw that. I actually had it printed out on the bench before I started.

[MTL_4runner]

If you followed that writeup the first time, then I'd give it one more try and then just replace the IAC. Also be sure not to skip the 12V bench test at the end of the process because that's the best way to work in the penetrant (WD40, etc) and make sure you hear a well defined "click" when the solenoid is actuating.