Throttle Body Cleaning - 1st Gen Tacomas - 3rd Gen 4runners

Last weekend I decided to clean the throttle body on my 4runner (Process is the same for 1st gen taquitos).

Decided to document the procedure In hopes it would benefit someone who likes do things on their own:

For this task, I picked up some throttle body cleaner, a rag, and my wife's toothbrush:



One of the most important steps in this procedure is to stare down the throttle for a good 2 or 3 minutes. This helps break down the carbon inside. The harder you stare, the more it breaks down and easier it is to clean. Sorta like WD-40 loosens up rusted nuts and bolts.



First step is removing the airbox assembly, loosen airbox bolts and straps:





unplug mass airflow sensor and any other connectors in the vicinity:



There will be a smaller airbox towards the firewall with some airlines connecting into it, remove the airhoses and the small airbox:





Don't forget the airhoses that run towards the front of the engine towards the piping of the airbox:





Loosening these thinner clamps will help removing the piping to the airbox:







Remove another plug, this one is right besides the accelerator cable:



Three cooling lines will be feeding into the throttle body, these can be removed also:







Another plug:



Remove the accelerator cable off the throttle, this can be done by clocking the body of the spring and sliding it out carefully:



Another picture of everything removed:



Remove the two top nuts that are holding the throttle in position:



Now remove the bottom bolts that are holding the throttle in position:



Pull off the throttle gently:



Take it to the operating table:



Generously spray inside the throttle body with cleaner and brush the carbon off with your wife's toothbrush and rag:



Carefully rotate the "door" to make sure all the carbon buildup has been cleaned out.

If you aren't bleeding, you aren't done:



Once you are satisfied with the removal of carbon, installation is reverse of removal.

 

*cough*

https://www.tacomaworld.com/threads/3-4l-w-etcs-tb-cleaning.324673/

maybe they should make us a sticky, als consider the 01-02 4Runner and 03-04 Tacoma used the ETCS and pre(years before) used IAC

 

I figured there was another one around here

 

I like 'em both. Very informative and I laughed a little too.
Thank you.

 

Great write up. Will read again, if for nothing besides entertainment.

There's no gasket to be replaced?

 

I didn't see a gasket when I took mine apart, figured it didn't need one. Unless someone in the past had already removed it and didn't gasket it..

@frizzman any input?

 

So by the time I get to the last step and I'm not bleeding do I have to start over?

 

yes

 

the only gasket was the one between the TB and plenum. since the ETCS has no separate IAC therefore no second gasket. most of the time you "could" re-use plenum one but might as well get a new one.

 

does it matter which way the throttle gasket goes?

 

Yes.

On my 3.4 it's obvious by the shape of the plenum.

See attached.

Also, those of us with IACs... be careful when cleaning the TB as to not spray gunk down into the IAC.

 

by Protusion, I am guessing its a "tab" that sticks up?

Last picture of the file you attached

 

I don't know what they hell they meant. But it's painfully obvious on how to install the gasket.

Also - stock gaskets have a "D" shape opening. Toyota sells one for supercharged(?) engines that are "O" shaped. Many people swear by the latter saying it increases performance. I swear by Toyota engineers knowing what they are doing when building these engines so I stick with the "D" shape.

 

As @Madjik_Man said, yes. I installed mine the wrong way and it threw a P0171 code which I chased for weeks...

When I clean my TB I remove the IAC valve from my TB and clean it real good, then test it by connecting to the battery to make sure it moves and doesn't stick, and finally replace the IAC gasket.

I feel like I remember reading somewhere that the flat side of the D shape is intended to break up or "mix" up the incoming intake flow so that any gases from the PCV system are mixed in thoroughly. Or something like that.

 

I know I'm a bit late to the party, I saw another writeup on TB cleaning from a couple years ago where he popped off the plate on the top of the TB and cleaned out the little ports that lead into the intake right near the flap. There is a coolant hose leading to this little reservoir thing, and I'm not sure what the function of it is. Or what it might be called. Does anybody know? Its clearly visible in the second picture of the OP. It has four philips bolts holding it on.

I cleaned my MAF and TB recently (04' 3.4L) and noticed a little gasket under the plate that I want to replace, but I have absolutely no idea of how to find it because I can't figure out what it's called.

This is the post I'm talking about where he pops it open https://www.tacomaworld.com/threads/3-4l-w-etcs-tb-cleaning.324673/

 

there really isn't a "gasket" under that top plate. It's sort of already part of the plate. it just makes contact to keep air out. this is essentially the IAC (those 4 port holes)

also that's not a coolant hose going to that part, only vacuum/air. the coolant lines are lower on the TB

 

That makes sense that it would be a vacuum line so you don't suck coolant into your intake. The reason I'm asking after the gasket is because there is a paper gasket for sure on mine that was pretty brittle and chipped a bit when I bumped it with the toothbrush. It's all together now (I pieced it together smoothly) and there aren't any issues but if I start having throttle or idle issues that's gonna be the first thing I look into. Also, it will be super quick and painless to change considering it is right on top of everything.

I may just go junkyard digging if I can't find one for a couple bucks somewhere. Thanks for the quick response.

 

I think the gasket is part of the TB itself now that you pointed it out, you can see the screw holes amidst the darker color. Mine did not have any cracking so that's probably why I didn't notice it. could probably make a new one from some thin material and just cut it out