I know there are TONS of threads on this topic but all mention DO NOT spray throttle body cleaner down the TB throat as it could cause damage. I have read in many places that this ONLY stands true for drive-by-wire throttle systems due to potential damage to sensors in there.

Since I have a GS400 (which is not drive-by-wire) can't I spray this CNC throttle body solution into the TB? Last time I cleaned the TB, I only cleaned the front of the "plenum" (flap) and I don't know if that really does anything. Also, I was told to do this cleaning when the car is HOT so that the carbon build up (residue) can break up easier.

Is the aforementioned correct? If so, I'm going to get on it tonight!

 

Separate the TB from the manifold and you will be safe. This is how i did mine on my 300. Also an old toothbrush helps with the cleaning of the carbon build up.

 

You don't need to do it while its hot - I'd do it after the car cools down, just use the TB cleaner and small toothbrush and a dirty rag.

 

It is ok to spray the CNC TB cleaner directly into the TB of the GS400. I've done it on my GS4 with no issues.. The results will be more effective than cleaning the inner lip of the TB. The engine will breathe, feel and sound different as a result.

 

Thanks Sean! I believe you and I'm going to run with it....I hope your giving me some good advice! lol

 

just cleaned mine over the weekend...world of difference! how often should you clean the throttle body?

 

DId you spray directly into the Tb or just cleaned around it?
I was wondering the same thing as RockALex because on the spray it says spray directly into the TB, all i did was just clean around it.

 

try not to spray inside the TB since youll get the carbon + cleaner inside the ports.. prolly cause other stuff inside to become dirty.

 

if your scared just spray it on the rag then clean it up in there. Thats what I did on my 430 a month ago and not a single problem.

 

yea i forgot to mention that part.. What he said! ^^^^^^^

 

well i just did mine at work on my 2001 gs430....my TB was FILTHY especially inside...

apparently we use a different MAF sensor on the gs430's mine doesnt look like a bullet like everyone elses... i DID spray inside the TB but mainly i sprayed a lint free rag and wiped it off/down. resetting battery right now as i seem to have a higher idle 1.6k and i think i normally have a 1k idle but who knows...we'll see what happens

 

Cleaned the TB today by spraying inside the TB, I followed the directions on the back of the can by spraying inside the TB for 10 sec then waiting for 10 sec then spraying again and etc... until the can was half empty.

Then I tried to start the car and i had to try about 3 times because it would choke when trying to crank it. Whens its cranking just feather the gas pedal and get the RPMs going a bit and when they stay steady just let the car run for about 3 min. When I was doing this i noticed a huge white cloud of smoke coming out of my exhaust for about 4 sec, then it cleared up.

Then turn the car off and just turn it on again and go for a quick drive. After the drive repeat the process by spraying inside the TB until u finish the can, make sure u do the 10 sec spray, 10 sec wait etc...

When you are done u will still have a slight problem turning the car one just feather the gas pedal to keep the RPMs up a bit then just let the car run for about 3 min. Go for another quick drive.

After the whole process one the second drive i noticed the car running smoother, and the idle was very smooth. But b4 this whole process I cleaned the TB Inside and out with a rag to make it look like it was brand new.

While your cleaning the TB you might as well clean out your MAF sensor you should get a pretty good result when your done.

Enjoy the smooth rides after wards *)

 

Since when does can throttle body cleaner ruin the TB? What do you think the dealer does? The thing to be worried about is the little straw DO NOT USE IT! If the straw goes in the intake, you have to take the TB off and fish it out, waste of time. The Toyota MAF sensors are pretty good, I never have to clean a MAF at Toyota. The reason why it idles high right away is because it is in open loop, specially when you start it up, it runs a cold start and is basically running really rich to warm up faster, as this is the same setup as a fast idle switch on a carb. The best way to do it is prop it open, spray in there, use a tooth brush, loosen the nasty stuff, use a rag and wipe it off, button it back up and your done.

 

I cleaned my GS400 throttle body almost 3 months ago and have had a high idle problem ever since. The car used to idle around 800 RPM even on cold mornings but since cleaning the TB it idles at 1300 RPM in the mornings even in my warm garage. Once the car fully warms up it idles normally. I read about another CL member having a similar problem here: https://www.clublexus.com/forums/per...-cleaning.html but my car reaches normal temperature as it always has. Any ideas?

Edit: I guess that was you, Rock-A-Lex, that had this issue

 

mine idled really high 1.6k after doing my TB cleaning but i just unplugged battery/let it sit for 20 mins and plugged it back up and its back to normal...will know bout improvement of gas mileage shortly as im bout halfway into my first full tank. i'll say this the TB was FILTHY!