1UZ-FE idle adjustment

[grazza]

Any 1UZ-FE experts out there?
My engine is idleing too fast and after reading some info on www.lextreme.com I think its because my Idle Control Valve (ICV) may be sticking, not surprising given the motor came out of a half-cut and had some surface corrosion.
So I am going to have a look at it tonight and make sure the spring is lubed up.

Anyway, does anyone know if its possible to have a manual idle adjuster fitted to the dash? Is there a ECU signal I can adjust with a pot or something?

The 1UZ-FE rotates more freely than the old six so maybe an idle adjuster will help with engine braking.

If I manage to fix the fast idle tonight i'll let y'all know...

[slowhilux]

Sounds like the ICV for sure. Most import Toyota motors have this problem. If the lube dont work, disconnect the hose that runs from the air intake to the ICV, and block both ends of it. There should be an idle screw on the TB somewhere, i will check for you tonite (this may depend on what version of 1UZ it is, too!)

Phill

[grazza]

Thanks Phil.
Cleaning the ICV did not make any difference.
When I took it off it seemed to work pretty well but I cleaned it up anyway. Strange thing it is though.
I will try removing the hose tomorrow morning (so I dont annoy the neighbours tonight!) Should I expect the idle to go up or down with the end sealed up?

I am wondering if the people who fitted the engine wired the idle circuit up correctly. The idle has always been fast and when I mentioned it to them they said it was "normal" (I dont deal with them anymore)

[slowhilux]

The ICV is controlled by the engine ECU. It lowers the idle as the water temp goes up, and then once the water temp reaches a certain value, the ECU shuts the stepper motor in the ICV right up (ie:- no air passing thru the ICV. The 1UZ should idle at around 750-850rpm. When you plug up the icv hoses, the idle will drop right down. The idle screw on the throttle body (i forgot to check last night if they have one!), if wound out, will slowly increase the idle, to whatever you want it to be.

Phill

[slowhilux]

OK, mate that i live with has a LS400 Lexus version (model number UCF11) motor in his MX83 Cressida. There is a small threaded grub screw with a lock nut directly above where the throttle cable ataches to the throttle body. Dont get this confused with the traction control ones, there are 2 others. Wind this graub screw in so that it will slightly adjust the throttle blade to desired idle speed.

Hope this helps,
Phill

[grazza]

Thanks Phil.
Will go and have a look for the screw.

I took the pipe from the ICV off, in preparation to sealing it, when I noticed that someone (the installers) had already blocked it off with a large bolt.

So anyway I removed the bolt and predictably the engine rev'ed very high.
When I was putting the bolt and pipe back I noticed a cable clamp close to a big intake pipe and sure enough, it had worn a hole in it. So I sealed it up and put it all back together.
Idle still high so does that mean the ICV is stuffed?
I will have a look for that grub screw soon...

[grazza]

Found the grub screw and adjusted the idle down - bloody beaut mate.
Will ask the guys who are fitting the Unichip next week if they think the ICV is stuffed. Will let you know the outcome, and the difference the Unichip makes. Although I live in sunny Queensland I think getting the ICV to work could be useful for when I do trips to colder climes...

On another topic, can you offer any advice with this:
http://www.outerlimits4x4.com/PHP_Modul ... hp?t=42009


thanks,
Grazza

[TWISTY]

My 1UZ in my 4Runner idles high too, but not all the time....most of the time when you pull up at lights etc...it'll idle high for 10 or so seconds, then drop down to the correct idle speed.

How did you go about lubing the spring up in the idle control grazza??

[POIDA]

Will ask the guys who are fitting the Unichip next week if they think the ICV is stuffed.

If the grub screw was adjusted up too high then the ICV cannot control the idle down low enough. It goes out of it's range. Perhaps it was just mal adjustment. If you were to continue to adjust the idle grub screw down but the computer keeps the idle up then I'd say the ICV would be OK.