A common problem for Cadillacs, and many other cars at that, is their reputation for getting a dirty throttle body due to carbon buildup. Dirty throttle bodies would eventually produce what many people would refer to as a "sticky gas pedal" and frequent stalls at stops. The simple fix for this common problem is one that can be done by anyone with the proper tools.

By now you may be wondering, what is the throttle body? In simple terms, the throttle body is a round opening that controls airflow. For a further explanation on how this works, read the article in the yellow box on this page: http://www.popularmechanics.com/automotive/sub_care_sat/1272341.html?page=3&c=y

Now, down to the nitty gritty...how can I clean the throttle body? Cleaning the throttle body is a simple process that this walkthrough will demonstrate. Let's start.

Tools Needed:
Ratchet with 9/32" bit.
Carb Cleaner (Top Gum Brand is used in this walkthrough)
Rag or Toothbrush (to clean)

Step 1: Remove the Air Intake. This can be done by simply pulling it off at the round opening at the top.

There is one sensor that may have to be unplugged (it should have red lining). In this walkthrough, there are a total of 3.

http://img.photobucket.com/albums/v714/slick07/tb4.jpg

Specifically, this is the air intake:
http://img.photobucket.com/albums/v714/slick07/tb42.jpg

Step 2; part 1: The removal of the air intake will expose the MAF screen.

http://img.photobucket.com/albums/v714/slick07/tb2.jpg

Specifically, this is the MAF screen:
http://img.photobucket.com/albums/v714/slick07/tb22.jpg

Step 2; part 2: Remove the MAF screen with a ratchet. (You will need a 9/32" bit)

The red outlines indicate where you should remove the screws. The blue outlines indicate sensors plugs that can/may be removed for easier access as previously mentioned. There are 3 screws, one is under the MAF screen, remove this one first to make things easier (it is the hardest to loosen because of its location).

http://img.photobucket.com/albums/v714/slick07/tb32.jpg

Step 3: The throttle body and throttle body blade ("blade" does not indicate that it is sharp) are now exposed.

The throttle body blade opens when the accelerator is pressed. It will need to be kept open in order for proper cleaning. In order to do this, you may lay something heavy on the accelerator (manually keeping it open will tire your hands).

http://img.photobucket.com/albums/v714/slick07/tb.jpg

Step 4: Proceed to clean the throttle body with Carb Cleaner.

You may either spray some on the actual blade and bore, or spray on a toothbrush and clean. DO NOT FORGET to clean the blade perimeter as well.

http://img.photobucket.com/albums/v714/slick07/tb5.jpg

After you are done cleaning the throttle body, reassemble everything by following these steps backwards. REMEMBER TO RE-CONNECT ALL UNPLUGGED SENSORS.

The total amount of time required for this task depends on how well you are aware with the location of certain objects. It may range from 30 minutes to 2 hours including cleaning.

-SL1CK

Nice write up. i wasnt sure how i should clean mine now i know how too. thanks im gonna do it tomarrow.

judging from the pictures it looks like this will work on my 2k1 deville, is that correct?

if so the owners manual says something about an electronic control pedal, which im guessing would eliminate the possibility of layin somethin on the pedal to keep the blade open

It should work for the 2k1 deville, although some parts may LOOK different and MAYBE require a different size ratchet bit.

Man its amazeing how the more things change the more they stay the same

Thanks for the great pics and instructions. That's exactly the problem I was having, sticky gas pedal and stalling at 30mph when slowing down from high speed. I was shocked how much crap was in my throttle body at 66k miles for my 99 deville. It looked like a used car's motor oil which was never changed. I went through 5 cotton rags to clean all that black junk out.

For that bottom screw, I had to use a 2 inch extension. And I don't know what it's called, but the lever where the wire is being pulled on that connects to the blade... I opened the blade then placed a wrench on the lever which kept the blade open. Oh, I was a bit concerned for a moment after I finished my task and attempted to start the car. The engine struggles like as if it's been flooded and revs up the engine multiple times like as if it's a misfire or something. After 45-60 secs, it calms down and runs fine.

For a guy who does decent amount of maintaince and repairs on his car... this project took me 1hr. Taking it all apart, cleaning, re-assemble, and turning the car on to purge the remaining cleaner out of the engine.

Thanks guys, this forum kicks ass.

so it is ok to leave excess cleaner in the throttle body?

Excess cleaner will not stay in the TB. It will drain out the front or the back and settle in the manifold where it will evaporate or be injested and burnt. Personally, I stick a rag in as far as I can get it and try to sop up as much of it as I can out of the manifold.

This is a great post. Very easy to follow. Is there anything else i should know about. I know its very important to not touch the mass air flow sensor. I have heard some people get some carb cleaner on the MAF and run into problems. I was just wondering if there is other things to be careful of.

Not much. It is pretty straight forward. Just don't get crazy if it is really carboned up and try to scrape it with anything metalic. Remember, the TB is aluminum (soft).

I cleaned my TB last nite. 98 STS 130,000 miles. This stuff/gunk/cabon was an 1/8" thick on the back side of the throttle blade and a 1/8" thick rim of it behind the throttle blade!! Inside the intake looks way thick with the gunk, I'm thinking of taking the intake off and cleaning it too! The best part was throttle responce I got after just cleaning it back to the intake!!!! Off idle throttle responce is awsome now!!! Now what will happen when I clean out the intake, my guess would be more power!! Port matching & porting an intake on hot rod V8 can be as high as 20hp! Maybe we need pictures/instructions how to remove and clean a North star intake?
Guy

My mom's 97 FSM states that this is a 30K mile cleaning interval.

I have tried to keep up on this on most of my cars that are EFI. I just installed a oil separator on my LT1 that should reduce this oil residue buildup from the PCV system.

http://collop.cz28.com/custom2.html gives a good description of it and why this is a good idea.

Excellent post SL1CK!

Great information...very easy to do on the 2000 STS as there is no MAF screen to remove. Mine was not that dirty, but no question it needed a cleaning. It took me about twenty minutes. So far the idle looks to have steadied out. I'll see over the next few days how critical this was to the idle problem. Thanks again. :burn:

Great post. Mine was identical to the pictures... did it Saturday, was a piece of cake.

My car started right up, but blew some smoke for about 30 seconds.... then cleared up.

Nice write up, nice pics. Thanks a million.....

A common problem for Cadillacs, and many other cars at that, is their reputation for getting a dirty throttle body due to carbon buildup. Dirty throttle bodies would eventually produce what many people would refer to as a "sticky gas pedal" and frequent stalls at stops. The simple fix for this common problem is one that can be done by anyone with the proper tools.

By now you may be wondering, what is the throttle body? In simple terms, the throttle body is a round opening that controls airflow. For a further explanation on how this works, read the article in the yellow box on this page: http://www.popularmechanics.com/automotive/sub_care_sat/1272341.html?page=3&c=y

Now, down to the nitty gritty...how can I clean the throttle body? Cleaning the throttle body is a simple process that this walkthrough will demonstrate. Let's start.

Tools Needed:
Ratchet with 9/32" bit.
Carb Cleaner (Top Gum Brand is used in this walkthrough)
Rag or Toothbrush (to clean)

Step 1: Remove the Air Intake. This can be done by simply pulling it off at the round opening at the top.

There is one sensor that may have to be unplugged (it should have red lining). In this walkthrough, there are a total of 3.

http://img.photobucket.com/albums/v714/slick07/tb4.jpg

Specifically, this is the air intake:
http://img.photobucket.com/albums/v714/slick07/tb42.jpg

Step 2; part 1: The removal of the air intake will expose the MAF screen.

http://img.photobucket.com/albums/v714/slick07/tb2.jpg

Specifically, this is the MAF screen:
http://img.photobucket.com/albums/v714/slick07/tb22.jpg

Step 2; part 2: Remove the MAF screen with a ratchet. (You will need a 9/32" bit)

The red outlines indicate where you should remove the screws. The blue outlines indicate sensors plugs that can/may be removed for easier access as previously mentioned. There are 3 screws, one is under the MAF screen, remove this one first to make things easier (it is the hardest to loosen because of its location).

http://img.photobucket.com/albums/v714/slick07/tb32.jpg

Step 3: The throttle body and throttle body blade ("blade" does not indicate that it is sharp) are now exposed.

The throttle body blade opens when the accelerator is pressed. It will need to be kept open in order for proper cleaning. In order to do this, you may lay something heavy on the accelerator (manually keeping it open will tire your hands).

http://img.photobucket.com/albums/v714/slick07/tb.jpg

Step 4: Proceed to clean the throttle body with Carb Cleaner.

You may either spray some on the actual blade and bore, or spray on a toothbrush and clean. DO NOT FORGET to clean the blade perimeter as well.

http://img.photobucket.com/albums/v714/slick07/tb5.jpg

After you are done cleaning the throttle body, reassemble everything by following these steps backwards. REMEMBER TO RE-CONNECT ALL UNPLUGGED SENSORS.

The total amount of time required for this task depends on how well you are aware with the location of certain objects. It may range from 30 minutes to 2 hours including cleaning.

-SL1CK

What a great tip. Like many others I had a sticky gas pedal. Just thought it was normal stuff. Such an easy fix. Many thanks.
Dave,
1997 concours

SL1CK,

I would like to nominate you for "Tech Tip Of The Month" Thanks a bunch for a very well thought out and illustrated tip. Can I coax you into a post about changing spark plugs in a 2000 STS? :burn:

I find my LT1 tends to get stickier in the winter months, primarily if I have the throttle body coolant bypassed.

Cleaning helps a lot. I don't recommend the throttle body coolant bypass due to the sticking in the winter. It doesn't do much if anything at all anyway.

What a great tip. Like many others I had a sticky gas pedal. Just thought it was normal stuff. Such an easy fix. Many thanks.
Dave,
1997 concours

Hey i just did mine...
and my dads...
and my moms (woah was hers hell!!!)
took about 2 hours to do them all no biggie at all great wright up i used it the 1st time a mth back and figured i owed you some props so slick muchas gracias

If you take a good monitor of your idle IAC counts before and after you will see the improvement.

IAC counts around (I believe) 128 show no need to perform it, but anything outside of that, it is needed.

SL1CK,
Can I coax you into a post about changing spark plugs in a 2000 STS? :burn:

I seriously would if I had a 2000 STS :rolleyes:

On my LT1, I was able to add a oil separator into the crank case breather air line which should reduce the needs for this cleaning.

http://web.camaross.com/forums/showthread.php?t=336407

http://lt1tech.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=6;t=003154

I can't seem to find a good pic of it, but I will take one on mine. It looks stock, so if you are creative, you can add this to the NorthStar.

This forum ROCKS!! Slick, you rule the rock! lol

So, Im picking up a 92 Deville with 91,000 from Texas any day now. Approximately what percentage or these Devilles are having this problem and should I just plan on cleaning the TB right away? Before symptoms and all?

Plan on doing it every 20K-30K or so.

It would be really good if you did it asap.

On the '92 (4.9), don't forget to rod out the two EGR tubes down in the TB. They will get carboned up.

This instruction works on a 1991 seville as well. It is a little easer to get too. Remove the air intake elbow and open the throttle. Alternate spray and swab the two ports untill clean. (A small swap about the size of a gun cleaner and you are in business.) The car now runns like it should and the gas millage is back where it should be. Thanks for the post.

I know how to clean throttle bodies, but when I did mine, the car started kind of hard as usual, but then the throttle seemed to be sticking slightly. It wasnt doing that before. I used to work at a Cadillac dealer and was always told to just place a screwdriver inside to keep the blade open (obviousely dont pry on the metal). Anyone have this probelm also? Maybe I just have to go drive it to let it settle out.

If the throttle is sticking, do it again. Spary the pivot points good, clean the perimiter of the throttle blade.

Went to clean the TB last night, (98 eldorado), and just for grins checked the service manual. Page 6-777 states "Do not use any solvent that contains methyl ethyl ketone, (MEK). This solvent may damage fuel system components."

Sure enough, the spray carb and choke cleaner I had contained MEK. Purchased some Carb Choke & Throttle Body Cleaner which has xylene and acetone as solvents.

Probably a good idea to use cleaners that are specifically for throttle bodys.

"Ride, boldly, Ride" - James Caan - Eldorado

Amen Brother- don't use old school carb cleaner on the throttle body. I think there is a coating on the blades that can be washed away with regular carburetor cleaner. Throttle body blades are different metal than an old quadrajet or holley blades. I am not sure why the coating is there even- Lubrication i think because a throttle body doesnt have the fuel flowing over it like a carbs blades do.
Anyway don't panic if you did it with the old stuff just remember if you start having sticking issues in the future.
Someody else might have better data on the coating and its purpose, i am going from memory and my stupid dial up precludes any kind of reasonable data search this century!
Matt

Did it and it made it better. What a pain in the ass compared to some of my other cars though.

This is a great howto!!!

My question is can I still do this to my Yukon with a 5.7L. the TB is horizontal (intake air comes from the top and goes down) so any solvent sprayed in will drop straight into the intake. Will this cause problems? Do I have to take my TB all the way off to clean it?

Thanks
-Robert-

Just hold the throttle plate open. No need to remove the TB. If the solvent goes into the manifold (I assume you meant vertical) it may be a little hard to start and will smoke a bit til it all gets burned out. You could also stuff a rag down there to absorb most of it. Just don't forget to remove it.

BEST cleaning is done removed. But you don't have to if you want to do it and make it better. You can get 90% with it on. Just takes some work.

Lurk on over to FullSizeChevy.com, in the tech section or How To article section should be all you need and a ton more..



This is a great howto!!!

My question is can I still do this to my Yukon with a 5.7L. the TB is horizontal (intake air comes from the top and goes down) so any solvent sprayed in will drop straight into the intake. Will this cause problems? Do I have to take my TB all the way off to clean it?

Thanks
-Robert-

Hey great write up! I usually clean my TB every other oil change. It's probably overkill, but I've had a dirty TB stall my vehicle out at stop lights during rush hour before:banghead: so I alwasy keep it clean now.

There is one thing though, YOU SHOULD NOT USE CARB CLEANER ON YOUR TB!!! There's a difference between carb cleaner and TB cleaner! TB cleaner won't damage the TB or electrical sensors where A LOT of carb cleaners will (most actually). Carb cleaners are more harsh than TB cleaners! I use and recommend using Valvolines TB/Carb cleaner. It works great and it has a unique spray nozzel that can spray in any direction, which means you can spray up & down and side to side and get erevy bit of the TB without holding the can upside down (which will normally stop a can from spraying!) Here's a pic of the can. You can also clean out your PCV with it too.

Walmart carb cleaner is HARSH, I mean wicked stuff. Be very very careful with it. It strips carbs down to bare aluminum is seconds. Avoid unless you want that.... All that irridite finish is gone.....

You can also buy a bored out (about 3 more mm) TB from ebay every now and then you'll see them for sell, from a guy down in Fl.

Not a bad deal is something like $150, and you'll get about 10 more hp

FL01SS good tip about the harshness!

N-star, would those work with our existing setups?

Great post i did it and it was soo dirty and grimme. the cars respones so much better now. good look

Excellent post

Nice! Thanks for the help, will clean mine tomorrow!!