Throttle body cleaning

[komichal]

Hi all,
I have cleaned my Yaris' throttle body some 50,000 km ago so it is probably time to do it again to keep hers 2SZ-FE running smoothly.
So far I have been always doing it in the way that I put ingition key to "1", pushed gas pedal and I used throttle body spray cleaner and a rag to remove the dirt. However, the throttle body has been always connected to the engine so I cleaned only the visible area.

I have read a few articles that it is actually good to unbolt the throttle body completely off the engine and to clean it comfortably outside, on a desk. From both sides.

1. Do you have any experience with it? Is it really just a matter of 3-4 bolts and a few connectors/hoses to get the TB out?
2. How do you open the flap when the TB is on the desk? AFAIK I cannot operate the flap by hand for drive-by-wire systems. But the flap edges are actually the most critical (and most dirty) parts. I guess I need to connect the wires back and use the throttle pedal to open the flap?
3. Any torque specs for screwing the TB back in?

Thanks folks.

[Brighton]

You can move the butterfly valve by hand. I usually use a paint mixing stick or something similar to hold it open when I clean them. Removing the throttle body from the car will let you do a much more thorough clean but it's a decent amount of work when compared to the performance change you'll get from cleaning it while installed on the car. Just make sure to have a new Throttle body gasket since the chances of it not ripping or leaking later are super slim.

[tmontague]

yup as stated above you can move the TB by hand but I would highly recommend you removed the electrical connector from the TB before you do any sort of manual moving of the butterfly valve.

I have only removed it from the car if the coolant was already being drained as the coolant lines will drip everywhere otherwise. I had a really dirty TB on my 2010 Outback and left it on the car to clean and it worked great and fixed the throttle response issues. On my Yaris I removed it from the car and cleaned it - I don't think removing it from the car is necessary unless it is all gummed up.

[komichal]

I actually did not know that TB is connected to the cooling hoses... Why is this so? Anyway, I will be replacing coolant as well so it seems like perfect timing. Still not sure if I will have the balls to move the flap manually, even when it is completely disconnected. I have read a lot of horror stories what happened when somebody tried to operate that manually....

[Brighton]

I can't think of many cars that don't have coolant running through them but it's got coolant lines running through it to warm up inlet air and regulate it (I think) You can disconnect the lines and it'll leak a few ounces which isn't bad but coolant is a pain to clean up and will smell awful when it burns off, so it's best to mitigate that as much as possible.

[salivanjack13]

As far as I know, you can open up this protective wall. After you do that hand-to-hand, you'll need to clean all the contaminants. After that, you should be able to close the flap quickly and avoid damage. But you need to do this carefully so that you don't cause other complications. Personally, I rarely do complete maintenance of appliances myself. More often than not, I turn to professionals so as not to make a mistake. For this, I use the help of sparklewash.com (https://sparklewash.com/upstate/). I am comfortable when I do most of the work, not myself. Maybe I will fully delegate the entire wash to these guys in the future.