Throttle Body Cleaning
Thread Starter
Intermediate
Joined: Feb 2006
Posts: 28
Likes: 0
From: Eldersburg Maryland
Throttle Body Cleaning
Hi,
I have a 1990 with an L98. It has roughly 24K miles on it. I took the Throttle Body (TB) off so I could clean it real good and replace the Idle Air Control (IAC). To do a proper cleaning, do I also remove the 7-8 torx bolts that holds the bottom piece of the TB where the two coolant lines and IAC attach? If so, when I get a gasket kit, will the kit come with a gasket for where this bottom piece mounts to the TB? To properly clean everything, do I just spray it up with some TB cleaner and/or brake cleaner...and let it sit in the stuff for a day or so?
Just want to make sure I get this as clean as possible. Thanks!
I have a 1990 with an L98. It has roughly 24K miles on it. I took the Throttle Body (TB) off so I could clean it real good and replace the Idle Air Control (IAC). To do a proper cleaning, do I also remove the 7-8 torx bolts that holds the bottom piece of the TB where the two coolant lines and IAC attach? If so, when I get a gasket kit, will the kit come with a gasket for where this bottom piece mounts to the TB? To properly clean everything, do I just spray it up with some TB cleaner and/or brake cleaner...and let it sit in the stuff for a day or so?
Just want to make sure I get this as clean as possible. Thanks!
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
Yes, the bottom plate has to come off. When you take it off there will probably be a lot of goo that can be removed with throttle body cleaner or carb cleaner. Under that plate are the channels that the air for the IAC uses so clean them as well as you can. If the gasket for this plate doesn't come with your gasket kit it can be purchased from any of the auto parts stores. Got mine at Advance Auto....WW
Last edited by WW7; Oct 16, 2009 at 04:41 AM.
Team Owner
Joined: Oct 2000
Posts: 96,443
Likes: 9
From: Fort Knox, KY
Cruise-In IV Veteran
Cruise-In VI Veteran
Cruise-In VII Veteran
Cruise-In VIII Veteran
Be sure and wet the gasket with a little motor oil before tightening to ensure an air-tight seal (vacuum leak).
I also like to use a large, plastic fruit bowl, an old toothbrush, some shop towels and an aerosol can of throttle body cleaner. Be sure and remove the Idle Air Control (IAC) motor and remove any carbon deposits on it using an aerosol can of IAC cleaner.
Do this about once a year as part of your preventive maintenance regimen. It really helps mellow the base idle, improves throttle response, and increases fuel economy, too.
I also like to use a large, plastic fruit bowl, an old toothbrush, some shop towels and an aerosol can of throttle body cleaner. Be sure and remove the Idle Air Control (IAC) motor and remove any carbon deposits on it using an aerosol can of IAC cleaner.
Do this about once a year as part of your preventive maintenance regimen. It really helps mellow the base idle, improves throttle response, and increases fuel economy, too.
Le Mans Master
Joined: Jul 2002
Posts: 5,818
Likes: 2
From: Alive and well in Burlington NC
I agree with all the above. As Onedef said, coat the gaskets with either a little motor oil or some high vacuum grease. Not oly does it prevent any air leaks, but makes it so much easier to take it apart next time. I use a stiff tooth brush and spray throttle body cleaner. No real need to soak the parts unless they are really nasty. Just spray on, scrub, spray off then wipe down with a shop towel.
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
Spray the bolts on the bottom of the IAC housing with penetrating fluid and let it work its way in there before you begin. Those bottom torx bolts are tiny and may be "frozen" in place which makes them easy to break/snap off.
Thread Starter
Intermediate
Joined: Feb 2006
Posts: 28
Likes: 0
From: Eldersburg Maryland
Thanks for the info folks! This is exactly what I was looking for. I'll go ahead and spray the torx bolts and let them sit a little bit...and then take everything apart and spray and brush .
.
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
Spray some TB cleaner around the gasket perimeter and if the idle picks up you have a vacuum leak , I didn't use anything on mine either and it sealed fine...WW
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
Drifting
Joined: Feb 2009
Posts: 1,302
Likes: 2
From: colchester CT
what do you do if one does snap off. It just happened to me. another member said I should be able to still remove the housing because those screws snap off in the body not the threaded part. any advice would be great. thanks
Drifting
Joined: Feb 2009
Posts: 1,302
Likes: 2
From: colchester CT
I say it would be a pain to try and drill it out to fix it. Do you have a pic of what bolt it was? As if it was one of the bolts for the coolant passage. You could just remove the coolant hoses from the throttle body by running the heater hose straight to the front of the block.
If it is one of the bolts for the IAC passage. I guess you could just leave it broke and run a small bead of RTV or something in that area when you bolt it back up. Or you could always get a new throttle body. That's just my guess.
If it is one of the bolts for the IAC passage. I guess you could just leave it broke and run a small bead of RTV or something in that area when you bolt it back up. Or you could always get a new throttle body. That's just my guess.
Instructor
Joined: Sep 2009
Posts: 194
Likes: 1
From: Northwest Indiana
By chance, would anyone have/know the part number for the IAC/coolant housing to throttle body gasket for a 1992 LT1?
It would be part #63 in the diagram here: http://www.compnine.com/index.php?u=...03&grouptype=B
I've tried searching the web sites for all the big part suppliers (Rock Auto, Advance Auto, AutoZone, Ecklers, Mid America, etc.) and everyone has the gasket that goes between the throttle body and the manifold but not the one that goes between the IAC housing and throttle body. I found a TB gasket "kit" at Rock Auto, but that only has the TB to manifold gasket and not the IAC housing to TB gasket.
I guess if all else fails, I can make one from some bulk gasket material using an Xacto blade.
Thanks in advance for any tips.
Ron
It would be part #63 in the diagram here: http://www.compnine.com/index.php?u=...03&grouptype=B
I've tried searching the web sites for all the big part suppliers (Rock Auto, Advance Auto, AutoZone, Ecklers, Mid America, etc.) and everyone has the gasket that goes between the throttle body and the manifold but not the one that goes between the IAC housing and throttle body. I found a TB gasket "kit" at Rock Auto, but that only has the TB to manifold gasket and not the IAC housing to TB gasket.
I guess if all else fails, I can make one from some bulk gasket material using an Xacto blade.
Thanks in advance for any tips.
Ron
Pro
Joined: Jan 2008
Posts: 657
Likes: 1
From: Sykesville Maryland
By chance, would anyone have/know the part number for the IAC/coolant housing to throttle body gasket for a 1992 LT1?
It would be part #63 in the diagram here: http://www.compnine.com/index.php?u=...03&grouptype=B
I've tried searching the web sites for all the big part suppliers (Rock Auto, Advance Auto, AutoZone, Ecklers, Mid America, etc.) and everyone has the gasket that goes between the throttle body and the manifold but not the one that goes between the IAC housing and throttle body. I found a TB gasket "kit" at Rock Auto, but that only has the TB to manifold gasket and not the IAC housing to TB gasket.
I guess if all else fails, I can make one from some bulk gasket material using an Xacto blade.
Thanks in advance for any tips.
Ron
It would be part #63 in the diagram here: http://www.compnine.com/index.php?u=...03&grouptype=B
I've tried searching the web sites for all the big part suppliers (Rock Auto, Advance Auto, AutoZone, Ecklers, Mid America, etc.) and everyone has the gasket that goes between the throttle body and the manifold but not the one that goes between the IAC housing and throttle body. I found a TB gasket "kit" at Rock Auto, but that only has the TB to manifold gasket and not the IAC housing to TB gasket.
I guess if all else fails, I can make one from some bulk gasket material using an Xacto blade.
Thanks in advance for any tips.
Ron
That diagram looks like my L98 TB. I didn't realize how similar they were.
This is what ACDelco has online for a '92 but quite different.
http://images.wrenchead.com/smartpag...US/219-607.jpg
I don't know anything about the LT1s but this is where I got my gasket kit.
Instructor
Joined: Sep 2009
Posts: 194
Likes: 1
From: Northwest Indiana
Hah! Found it! About half way down the page. "TBI Gasket Kit".
http://catalog.oehq.com/ShopByVehicl...=True&rewrite=
Oehq.com looks like a pretty useful source for parts.
http://catalog.oehq.com/ShopByVehicl...=True&rewrite=
Oehq.com looks like a pretty useful source for parts.
Le Mans Master
Joined: Jan 2010
Posts: 8,553
Likes: 3
Hah! Found it! About half way down the page. "TBI Gasket Kit".
http://catalog.oehq.com/ShopByVehicl...=True&rewrite=
Oehq.com looks like a pretty useful source for parts.
http://catalog.oehq.com/ShopByVehicl...=True&rewrite=
Oehq.com looks like a pretty useful source for parts.
Hey, want to hook up and have a "Dash Party" soon? I need to remove my dash again and re-wire aka: fix, my stereo connection. I "might" just go buy a better HU for it at BB. I fig we could tackle that AC button that doesn't work at the same time.
?
