Lvangundy

I did a little cleaning (finally got the drive to do it) on the TB and was suprised at how black and crusted it was.

No improvement in idle, revving, or performance though.

These pics show a more clean area as they were taken after I started spraying and scrubbing.

Used a hard wire brush and some STP throttle body cleaner.

Lvangundy

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Larger view

Lvangundy

On the freeway the engine feels better. Less having to push the gas before it does anything.

FLjbird

Wow...how many miles on your ride? I took mine apart thinking it would be dirty as a typical TB would be and to my surprise...it was spotless!!! And I do mean SPOTLESS. Seriously...this thing did not have a spec of gunk on it..nothing...perfectly shiny brass. This doesn't sound like a big deal, but you have to understand...my baby has 208K on it..and doesn't burn a drop of oil...nothing. Maybe I have one of the lucky ones...

GA400

Lee,

Since Fljbird mentions his is so clean, I wonder if it could be due to the gas in California having special additives to reduce pollution?
Just a thought....
If it is so dirty where it is visible, it is probably dirty further downstream, where you can't reach. Do you run a fuel injector cleaner through your gas on a regular basis? Just trying to think of something that may help

GA400

FLjbird

Hey...just thought of something...I know in the SC's..you have to run 93 or higher octane per Lexus....should be the same for the LS's right? Have you owned the car it's whole life...maybe the prior owners didn't know that.....hmmmm

Lvangundy

151K miles.

Yes, even as much as I cleaned out, there was still some carbon inside the intake manifold chamber thing.

I would have LOVED to rip off the manifold, but have NO idea how to get it off. Better suited for a whole day project.

Lvangundy

FlJbird - Are you sure you removed the thorrotle body and looked inside? Not just passed the plastic intake pipe on the left, but actually removing the unit with the butterfly valve as shown in the pics. At 200K+ miles I'd BET you have some carbon buildup further into the TB or intake manifold.