Another IACV Post

Hi All:

So I decided to change my fuel filter on my '04, DC 3RZ with 59k miles, and at the same time clean the throttle body and plenum. I also took off the IACV from the TB and cleaned the best I could with TB cleaner and little nylon brush. Everything was actually pretty clean as I probably did this a bit too early but anyway, I figure can't hurt right? Put everything back and I get the high idle (~2k) problem that after researching and found out to be a pretty common problem. I got some codes, I don't even know which ones but the one that was pretty consistent was the lean mixture one (sorry forgot #). I was pulling the codes with my ScanGauge and kept clearing it, praying my truck would heal on its own. After a couple trial runs, the problem changed to the idle surge problem (~1k to 2k).

So I took off the TB and IACV again and took a closer look at the IACV. It was slightly open. I couldn't remove the connector piece because I could not find any store that had the 5-point torx bit. I measured resistance and I was getting ~3M and ~46K values across the RSC/RSO terminals. I then applied 12vdc to the RSC/RSO terminals and nothing happened. Then I was sure the problem was the valve, so in the meantime, I ordered a replacement IACV from Amazon and 5-point torx bit set. Swapped out my original ones with the Amazon
(

$30 AUTOKAY Idle Air Control Motor Valve for Toyota 4Runner Tacoma IACV 2227075050

https://www.amazon.com/gp/product/B012AD8I8U/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1 ) one and high idle went away. Idles at around 700 when warm.

At the same time, I wanted to do some investigation with my original IACV, so I removed the connector piece from the original valve body with my new torx bit and the spindle piece was really stuck. It was so stuck I had to get a wrench to break it loose, and I had sprayed some PB blaster on the barrel part the day before. I shot more TB cleaner and the barrel spins really nice. I put the connector piece back and applied 12vdc and heard it move. So it got me thinking, was my IACV stuck this whole time and my truck was operating as normal as I could tell?? It's hard for me to believe the cleaning made my IACV get the barrel so stuck as it did. What do you make of it?

Thanks for listening.

 

Thanks for taking the time to investgate your problem and post here.

It's possible that your first cleaning washed some gunk down into the valve and it dried there. Was it stuck like that before the cleaning?

 

Possible, yes but my belief is unlikely. I think it was slightly opened when I first looked in the port hole when I first removed the TB assembly. But I didn't test it to see if it moved or not and I didn't have the correct torx to remove the connector piece to see if the barrel was indeed stuck. I just cleaned TB and IACV as best I could with the IACV still attached. I didn't want to mess with the IACV philips screws because it didn't look too dirty so why risk stripping the screws. Also, I don't remember my exact RPM #'s before the TB removal. I would say though, my idle does seem a tad slower all around (cold & warm). Anyway, thanks for reading.

 

Cleaning them for me has always been a death blow to the part, I have replaced mine once in 267,000 miles. I have had luck cleaning one for a friend but out of six, I’ve replaced five, they get stuck after these old gals get up in age.

 

Luv,

So you don't clean yours since you had only 1 to replace in those many miles?

The ones you had to replace, couldn't you have removed the connector piece and free it up similar to what I did? Or did the connector piece not work too in those situations?

IF my connector piece fried, what I was thinking of doing was taking the connector piece from the Amazon.com unit and swapping it on my original valve body. The original valve body seems to be constructed better than the Amazon.com one.

 

Seems to have a lot to do with the electric piece sticking like they do on airbrakes. The mechanics of the part are very solid and can be cleaned like new it’s just the solenoid to it goes bad, the fix for me has been to buy factory parts for this, the whole darned valve is around 250.00. The factory puts silicone over the solenoid screws but still can be removed, did this every time and only fixed one of them but Im sure you could find the electric solenoid if you are persistent because the valve is very simple to unstick and getting that piece only could save alot, I think when the valve gets mechanically stuck it fries out the solenoid making it easier to buy a whole new one. Hence why the stealership puts silicone glue over their screws they want you to buy a whole new one. I would stick to Denso for the part Don’t trust any other part for that.