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TB and IAC (idle air control) valve cleaning in a 1999 ETC

197K views 56 replies 31 participants last post by  ignatiusm1992 
#1 ·
So this morning, after making a pitstop on the way into work, the car would not stay on—it would stall.

If I applied the gas, no problem... But as soon as I let go the rpms would drop and car would stall.

I checked the carputer for any codes or clues... None. Luckily Ranger was around and pointed me in the right direction = dirty TB plate or IAC.

So here's what happened next.

I cautiously drove back home with one foot on the gas, the other on the brake (not allowing the RPMs to drop below 1000). Pictorial of the surgery, below.


This isn't as good as SL1CKs, but it is for the 2000+ which is quite simpler!

It also shows the IAC valve, which is so easy to take out and clean, but so expensive to replace!



Behold... my clean engine bay. It's more fun to work on a clean engine. I like to keep it clean!



To remove the air intake duct, simply unscrew the two screws on the air filter housing, and




unscrew the slotted bolt holding the intake to the TB.


Here is the IAC plug, two phillips screws hold it in.



When you take it out (After unplugging it) here is the port hole, clean this well too.


Here is the IAC valve, and it's two fastening screws. I cleaned it with electric parts cleaner, so if any of the solvent leaks into the electric motor or windings, it doesn't harm them as it's non-conducive.



This is a dirty IAC valve. The shaft is supposed to be shiny metal, not black soot.



Remove the duct work (unplug MAF sensor plug first)


Dirty TB



Spray it with the TB cleaner. I use a Toothbrush as well.



After the cleaning, the edges are clean and the back of the throttle plate (WOT, shown here) should be clean, as well as the mating area with the TB. Don't worry about the stuff further in, that'll dirty up in no time and does not affect operation.



not everything that shines is gold--this is platinum jk :histeric:


The rags will be really dirty.


The heroes of the tale! The electric parts cleaner saved my EGR valve on the Eldorado ETC I owned... u can use regular TB cleaner, but allegedly if you get the electronic windings wet with it, it can become toast! I used the Electric parts cleaner on the $349 retail price IAC.
 
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#10 ·
Re: Cleaning the TB & IAC valve on a 2000+ Northstar

My 2000 DTS was having the exact same problem this week and I thought it was my battery so I took it to get it checked and it was fine...then I thought maybe the alternator or starter...nope??? I stumbled across your post and did exactly as you posted and it starts up fine now...thanks :)
 
#11 ·
I just took mine out to clean it but I had to be careful because the black part would have shot out due to the inner spring. Does this mean mine is broken and has will come apart? I could easily take mine apart. The plunger slides in and out VERY easily. I cleaned it and put it back together and started it up and now my 2002 Deville is idling at 1300+ RPMs.:cookoo:

Please help. I started this because i was getting a P0507 code.
 
#12 ·
I just took mine out to clean it but I had to be careful because the black part would have shot out due to the inner spring. Does this mean mine is broken and has will come apart? I could easily take mine apart. The plunger slides in and out VERY easily. I cleaned it and put it back together and started it up and now my 2002 Deville is idling at 1300+ RPMs.:cookoo:
Yikes... yeah the IAC I didn't touch. It went bad anyway, about a year ago (much after writing this tutorial).

This is the one I had to buy... it's expensive but this was the best price I found on a new part: ACDelco 214-1098 Idle Air Control Valve Kit http://www.amazon.com/ACDelco-214-1098-Idle-Control-Valve

In the meantime, if the iAC is cycling, you can unplug it when the RPMs are at Idle range with the AC on. I kept it that way for a few weeks while the new part arrived.
 
#15 · (Edited)
i have a 2000 cadillac sls and i didnt understand what u meant by unplugging the MAF sensor and when u took the IACV out what did you use for cleaning the port hole?
Here's your 2000 - 2004 intake ducting setup - the MAF sensor is over next to the air filter adapter - has a plug in top - 5 wires. Don't break a wire - the connector has a safety lock........

Use hobby pipe cleaners - fuzzy wires - to clean out the IAC valve bore in the TB.

You might consider removing the intake duct resonator and closing the hole with a suitable plug which can be clamped: ANY air leak in that intake duct and you get all sorts of mixture problems and a poor idle. Use a suitable Philips screw in the air filter/PCM box cover.
 

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#14 ·
Use TB cleaner. I still have Gumout carb cleaner and use it, though "technically" I've heard it said not to. I've had no problems and see no reason not to.

Most of the time all you need to clean is the TB. If you still have an idle low or high problem, then clean the IAC valve.

Look at picture #1. See the plug on top of the intake duct between the two strap clamps? That's the MAF sensor plug. You have to unplug it in order to remove the intake ducting.
 
#16 ·
Re: Cleaning the TB & IAC valve on a 2000+ Northstar

So two days ago, I driving on the highway around 60 mph. I needed to get around the vehicle in front of me so that I wouldn't miss my exit, so I had to punch it up to to around 75'ish to go around. After that, I smelled something burning (for only a couple of seconds). After getting off the highway exit, I noticed that my car was idling kind of high.

The next morning, on the way to work, I noticed it again. I had to mash on the break at stop lights because my car was idling around +1000 rpms.

I did some research (internet), and found this thread and forum. (I drive a 2003 cadillac deville BTW)

I pulled the air filter housing, removed the IAC valve, and cleaned the throttle body.

Started her up, and now she's down to 700 rpms. Purrs like a kitten. Thanks for all the help guys, much appreciated.

Now all I have to do is work on the gas gauge.
 
#18 ·
Re: Cleaning the TB & IAC valve on a 2000+ Northstar

I just finished cleaning my throttle body for the first time. I also replaced the air filter. It definitely runs a little smoother and the gas pedal doesn't "stick" after you let off it and then reapply it. Not sure if it's in my head, but I believe there is a little more power too.

After reading many threads about throttle body cleaning, I remember seeing this picture...

http://i66.photobucket.com/albums/h2...c/IMG_0690.jpg

On my car, I saw where it comes from, however, do I have to unscrew it and clean this also?

Thanks to mtflight for the directions and pictures on how to do this.
 
#20 ·
Thank you for posting this tutorial. I am actually going threw this process right now. I just thought of a few questions while doing this. What if my after market car alarm goes off in the process. Can I start my car with the iac out? And. My throttle body door isn't open. Should I manually open it from the side to clean it better. And last. Should I clean all the way down by and on the springs of my IAC thing?
 
#21 ·
I want to thank you for making this tutorial. It helped me out a good bit. But I have some questions and things to add of my own. My engine was idling very low. Shaking hard at 650. And then I cleaned the tb and IAC and it was idling smooth at a nice 700. But here's my input.

I do strongly.recommend the use of pipe cleaners. The electronics cleaner solution melts plastic. If only I had a picture of my mess lol.

And now my questions

I saw you had the tb in the open position.
Mine wasn't. Do I open it manually from the side to clean the inside.

When cleaning my IAC. Do I clean the spring as well and anything I can get to without manipulating the controller.

Which solution did you use to clean the inside IAC port? Electric or tb cleaner?
 
#22 ·
Hey thanks for the compliment. Pipe cleaners sound like a good idea. The electronics parts cleaner isn't supposed to damage plastics, that's the only reason I suggested it. Using TB or Carb cleaner on the IAC could spell disaster.

I just cleaned the TB on my Eldo (I no longer have the DHS), and I was trying to figure out how I opened the TB. I know I used the wire and a screwdriver in some creative way. This time I just pulled the plastic lever and held it there with one hand as I cleaned the TB with the other.

You may not need to clean the IAC. but do not use TB cleaner for the IAC. You can use TB cleaner for the port, just not the little pricey thingamadoo. I hope this helps
 
#23 ·
Thank you for this thread. I was just about to buy a torque wrench and test the torque on the intake bolts. Saved me a small hassle. I didn't do the throttle body yet but will tomorrow since we got rain but my '01 Seville STS runs like brand new now. Well it actually took two crankshaft position sensors, a map sensor, an oil switch, the intake plenum, a knock sensor that I decided to replace anyways since I was in the intake; starter cost too much, a piece of pvc for a broken vacuum tube, and cleaning the IAC and now she's just like new.

I don't post often but this thread and others have helped me in great times of need. Thanks to all of you. Sorry if I'm threadjacking. I can post in a new thread if I need too.
 
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