High idle problem

Guys need some help!
Have a 01 Tacoma 2.7 that when started idles around 1400rpm then raises to 1900 when warm and doesn’t have any codes. I have changed the temp control sensor, upstream o2, thermostat, checked the tps by doing voltage check while opening throttle plate, cleaned maf, checked and cleaned throttle body, cleaned the idle control valve under throttle body, and ran vacuum check and checked for leaks with carb cleaner. Sorry for the long post, just really at a loss here and could use some ideas. thanks guys!

 

Time for a Throttle body rebore

 

I remember someone recently pulled out their throttle body and you could see the light shinning through.

 

http://www.maxbore.com/

 

Throttle plate seats tight no light gaps no slop on the control arm either, not really a mechanic so how would a guy know that’s the issue?

 

Hilljack, sounds like your throttle body is probably ok. When you look at the throttle body, does it close completely on its own with the spring? Or can you close it further by twisting the mechanism? I had to adjust mine a little after i cleaned mine.

Have you tested your idle air control valve? Could be stuck.

 

It does close completely, adjusted idle screws out and couldn’t close anymore by hand. Had a scan ran on it and showed the maf was at 1% on the Research I’ve done looks like at idle it should be between 5-7%. Gonna try and replace the maf and see what happens

 

If you know someone else with a similar tacoma you can always switch for a few minutes to make sure. It should be evident right away. If you’re close to Portland Oregon I’d let you use mine. Throwing parts at an issue sucks. Does the value respond to throttle changes?

 

Thanks sir,
the value stays at 1% regardless of rpm. Cleaned it good and still the same, hopefully that will do it

 

I had a high idle issue for about a year, no codes and high fuel trims. Ran all sorts of diagnostics and smoke tests and all that, couldn't rule out the IAC through voltage testing, and suspected my throttle body to be the issue as it was worn out. Almost went with a rebore with Maxbore.com as suggested by Black Dog, but because I couldn't rule out IAC, I purchased a new TB with both sensors. Check out toyotapartsdeal, I paid about $400 shipped for a new TB, which was a good deal considering the price of a IAC just by itself. Plus you wont be without your truck for several weeks waiting for your TB to be serviced. However, if you choose to, Maxbore seems to be the best and most reliable (if not only that i've seen) place to send your TB to. Good luck!

 

Thanks for the info Codosa, I appreciate all the help.

 

with a large pair of pliers squeeze the vacuum line from the brake vacuum booster to the intake or take it off and plug it with your thumb. Do the same with the PCV valve. I doubt that these are your issues because you would be getting codes... just eliminating the obvious and free things.

 

Thanks, already checked that. Does idle down when removing the vac line to the brake booster but idles rough, what would this indicate glamisman? I did put a vac gauge on the intake port and showed vac good according to the gauge.
Thanks for any help, about to drive me crazy!

 

Did you just spray out the iac or take it apart and clean? If you didn't take it apart I'd suggest trying that before swapping parts.

 

Took IAC off throttle body and cleaned with cleaner and a old tooth brush. Had a scanner put on and had some confusing readings, man I’m lost!

 

Airflow rate 1.1??

 

FYI replaced the maf with a new one from advance auto... no change! Luckily the guys at advance let me return.

 

Do you know if the the IAC is actually working?

 

How old are the spark plugs?