99 GS4 with 83,500 miles.

I'll let the pictures speak for themselves.

Before:

 

Where's the after pic???

 

And after:

 

Here's what I used to tackle the job:

 

If your car is a few years old and you haven't done this yet, I highly recommend it. I am not the most mechanically inclined person, but even if you take your time, it's no more than 30 minutes start to finish.

And I have to give credit where credit is due. If it weren't for GUNRU-GS4, I wouldn't have even attempted this project. PM me if you have any questions.

e

 

Okay, now for some initial observations.

As everyone else has said, the car started a little rough and idled at about 1,000-1,200 rpm for about 10 minutes. Once it calmed down, I noticed 3 major differences/improvements.

First, previously when I used to start my car, the car would fire up at around 1,500 RPMs and then drop quickly all the way back down to 400 or so, and then pop up to 500, which is about where it would idle. Now, when I start the car, it still starts at around 1,500 or so, but the drop down to idle is much more gradual and smooth. Definitely improvement there.

Second, the car now idles at around 700 rpm with the A/C on, which is 200 more than it used to. I view this as a good thing.

Third, and most importantly, the hesitation off the line is completely gone. When I used to press on the gas pedal, the car would hesitate for a split second, and then lurch forward. Now, when I press on the gas, the car just goes. There's absolutely no hesitation at all.

This was definitely worth the $5 for the TB cleaner and 30 minutes of my time.

e

 

can you include some instructions or steps on this DYI?
thanks in advance..

JC

 

Sure, I'd be glad too. It was easy. Unfortunately, I don't have pictures, but it's really not that hard.

(1) Take off the engine cover. There are 2 10mm bolts and 2 10mm bolt caps holding it in place.

(2) Once the engine cover is off, you need to take off the black box immediately to the left of the engine (as you're looking at it). The air intake tube coming out of the filter box and going into the throttle body is attached to and a part of this black box. First, take a screwdriver and loosen the clamps holding the air intake to the filter box and to the throttle body. Second, remove the 2 bolts that are holding the black box to the engine (one is in the back and the other is on the left side). Third, remove the 3 vacuum tubes that are attached to the black box. The vacuum tubes are attached to the box with pressure clips. Just squeeze the clips and pull off the rubber tubes. Lastly, remove the air intake tube from both the filter box and the throttle body. The air intake tube is accordian-like where it attaches to the filter box, so it comes off pretty easily. I had to apply a little force to remove the air intake tube from the throttle body.

(3) Take your can of throttle body cleaner, spray it on a rag, and wipe away. I also used a toothbrush to scrape away some of the gunk (per Gunru-GS4's suggestion). In fact, the toothbrush came in handy because I was able to wedge it into the throttle body to hold the butterfly cover open while I was cleaning. Some people say you're not supposed to spray throttle body cleaner directly into the TB, but my tech told me it was not a problem to do that. The only part you really need to clean is the butterfly cover and the part of the TB in front of it (towards the front of the car).

(4) Once clean, put everything back together in reverse order.

Hope this helps. Give me a second and I'll find some pictures of what I'm talking about.

 

Here's a picture of the engine cover with the 4 bolt locations. I know it's obvious, but some people might not know about it. Today was the first day I had ever taken mine off. The black box is located under the left side of the engine cover.

 

Here is a picture of the black box (showing 1of the 3 vacuum tubes). If you look closely, you can also see one of the bolts that attaches the black box to the engine compartment (it's right next to the green jug -- I should know what that is, but I don't).

 

And here is a picture showing the 2 remaining vacuum tubes. The other bolt holding the black box in place is to the left of the hand (you can see it in this picture).

 

Awesome write up. I'll be running to Kragens this weekend.

 

Nice! I noticed better fuel economy. After I did all the cleaning stuff for my car, i went from averaging 12.5mpg to 14.5mpg

 

good work e. I guess you couldn't watch your old GS get the treatment without helping out your own GS too, huh?

now you have me wondering how mine looks. I'll have to give it a shot. I wonder if the GS430 is exactly the same?

 

It should be the same.