Howdy.
99 5vz testing the IAC valve (which along with the TB was pretty caked up with carbon).

It does not seem to be closing all the way (testing as per fsm). +B to 12V, rbC or rbO for close/open.
Open it moves, close it does not go all the way closed. Did I trash coil? qien sabe. But here we are.

OEM in range of $230 ish. Bummer.
Can find others (obviously ChynaCo knockoffs?) for as cheap as $20.
But did find Bezos&Co for $47 or ebay for $45. Looks like its Isumo Co brand.

Any thoughts? Thanks in advance.

 

I'm not sure about on a 99, or on a 5vz, but the IACVs in the earlier trucks have an adjustment screw I believe. Maybe there's a way to adjust it like the older ones?

 

Yes, there is a plate covering what looks to be a pivot end. Guess I won't break it more by seeing. Thanks.

 

I know there was a thread not that long ago about taking the IACV apart and cleaning it, and even shows which way to adjust the screw and what those adjustments do, but I can't seem to find it.

Again, this was for earlier IACVs, so I'm not positive it will be any help. The design of it might be close enough that you can figure out exactly how to adjust yours though.

 

i just recently went through this with my 1999 2.7. now i know yours is a 5vz but i imagine they operate similarly.

min was not opening fully and also getting stuck while trying to close. cleaned it and re bench tested and still jamming and acting slow and weak.

i eventually found that they aren't suppose close fully, they stay open about 1/4 or 1/8. but they do need to open fully and rather quickly.

now i made the mistake of buying Chinese amazon stuff and it was a waste of 60$ the valve i got worked worse than my old malfunctioning OEM one.

i tried everything to get the new Chinese one to work better but it would not, i tried putting the OEM Toyota coil on it...nothing same.
i than realized the Chinese one was gutted and empty on the side where the spring and cam piece and adjustment plate are. i never installed it and decided to just put the old OEM one back in.

bought a new OEM one for 230$ online and bench tested it, and this one was bad ass, freaking snapped open so quick and clean, closed (slightly open still) just as quickly. it felt like it had a good strong coil pack too compared to the Chinese one

and it fixed like 90% of my idling and cold start issues....although not 100% because it allowed me to find other issues that still present but weren't noticeable while the IAC was bad.

save yourself the head ache and just get Toyota, not to mention the casting on the Chinese one was bad and i don't think it would have sealed the coolant from the intake anyways

also get a gasket from Toyota, the Chinese one came with one but it was significantly thinner in diameter and felt like it was fragile

 

Excellent, thank you.
I had actually took it apart and cleaned it, etc over a month ago. And now can't recall if/how much I left the "closed opening" at.
I had also sent the TB off to get fixed. I had that air gap around the plate body, pretty bigly. Got the unit back last week or two. For sure no gap now.