C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

throttle body cleaning

Thread Tools
 
Search this Thread
 
Old Apr 23, 2006 | 09:03 AM
  #1  
mudslide's Avatar
mudslide
Thread Starter
Racer
15 Year Member
 
Joined: Sep 2005
Posts: 385
Likes: 8
From: north branford ct
Default throttle body cleaning

On my 1990 L98 with 54,000 on the engine I want to fix a slight rough idle and slight jerking when I am going slow and steady about 1500 rpms.So I thought I would clean the throttle body and the IAC,then adjust the TPS. how do I go about cleaning the TB --on the car or off --carb cleaner or something else. Also whats involved with getting the IAC valve out. Thanks for your help-Walter
Reply
Old Apr 23, 2006 | 09:09 AM
  #2  
patsfan's Avatar
patsfan
Drifting
 
Joined: Jun 2005
Posts: 1,781
Likes: 0
From: Swanton VT 2000 Navy Blue Mettalic M6 / 1991 Auto - Steel Blue 68,500 R.I.P
Default

I iv'e been told the best way is to take it off and do it . I'm going to do mine when I do some other projects Next Thurs/Friday .

Heres a link for the Techtips here on the CorvetteForum . I find the techtips that the forum offers ( It appears there written by forum members ) to be quite helpful

https://www.corvetteforum.com/techti...=195&TopicID=2


Good luck ,

PatsFan
Reply
Old Apr 23, 2006 | 10:13 AM
  #3  
mseven's Avatar
mseven
Le Mans Master
 
Joined: Feb 2005
Posts: 5,146
Likes: 3
From: The Motor City
Default

Originally Posted by mudslide
On my 1990 L98 with 54,000 on the engine I want to fix a slight rough idle and slight jerking when I am going slow and steady about 1500 rpms.So I thought I would clean the throttle body and the IAC,then adjust the TPS. how do I go about cleaning the TB --on the car or off --carb cleaner or something else. Also whats involved with getting the IAC valve out. Thanks for your help-Walter
Definetly taking it off, and apart allows a more thorough cleaning with TB cleaner some small brushes etc. You will need a gasket set some TB cleaner, rags, and small brushes. After removing TB, and you begin taking it apart you will be removing the bottom portion that holds the IAC. After unthreading it, you may have to wiggle it side to side GENTLY to remove it. Be carefull not to damage the pintel. Make sure this area is cleaned of all carbon build ups.
When re-installing IAC, measure from base flange (w/gasket off)to tip if it is over 25mm you will have to hold the base and push in the pintell to retract it. Check the TPS w/a vohm meter to see if it is fuctioning correctly w/no dead spots in voltage and for setting at idle key on, engine off. I would also recheck the min. air (idle) setting.

Last edited by mseven; Apr 23, 2006 at 10:22 AM.
Reply
Old Apr 23, 2006 | 11:20 AM
  #4  
vader86's Avatar
vader86
Team Owner
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Sep 2001
Posts: 62,187
Likes: 1,741
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Default

my website has a procedure for TPS/IAC
Reply
Old Apr 24, 2006 | 12:25 PM
  #5  
onedef92's Avatar
onedef92
Team Owner
20 Year Member
 
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
Default

After you remove it, buy a can of that Valvoline SynTech TB cleaner. Use some shop towels and an old toothbrush to clean the assembly up real good. You might want to even take a rag and dab some brake parts cleaner on it and clean out the plenum ports, too.

The Valvoline TB cleaner runs about $2 a can at NAPA and other auto parts stores.

I just removed and cleaned my TB and IAC motor this past weekend and my base idle has been restored and the throttle response is much improved.
Reply
Old Apr 24, 2006 | 06:35 PM
  #6  
mudslide's Avatar
mudslide
Thread Starter
Racer
15 Year Member
 
Joined: Sep 2005
Posts: 385
Likes: 8
From: north branford ct
Default

THanks guys but im not haveing the same luck --the car still idles like crap after all that--runs good under power but not steady or at idle
Reply
Old Apr 24, 2006 | 06:40 PM
  #7  
MR NICE's Avatar
MR NICE
Drifting
 
Joined: Nov 2005
Posts: 1,361
Likes: 0
From: Downriver Mi.
Default

Originally Posted by mudslide
THanks guys but im not haveing the same luck --the car still idles like crap after all that--runs good under power but not steady or at idle
Maybe you have a dirty injector or bad tune up part.
Reply
Old Apr 24, 2006 | 06:48 PM
  #8  
mudslide's Avatar
mudslide
Thread Starter
Racer
15 Year Member
 
Joined: Sep 2005
Posts: 385
Likes: 8
From: north branford ct
Default

Dont know , if it was wires I would feel it under exceleration -cap ?? rotor?? Or maybe a bad Iac just because I cleaned it probably dosnt mean its ok. I dont have a tool to check it
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Corvettes to Drive Before You Die!

 Joe Kucinski
story-1

Corvette & Porsche 911: How Two Icons Conquered the Last 25 Years

 Joe Kucinski
story-2

2027 Chevrolet Silverado 1500 First Look: Everything You NEED to Know!

 Michael S. Palmer
story-3

5 Best & 5 Worst Corvette Daily Drivers

 Joe Kucinski
story-4

The Headlights of Every Corvette Generation Explained

 Joe Kucinski
story-5

5 Best & 5 Most Overrated Corvette Track Packages of All Time!

 Joe Kucinski
story-6

Every 2027 Corvette Engine Explained

 Joe Kucinski
story-7

Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette

 Verdad Gallardo
story-8

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-9

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
Old Apr 24, 2006 | 06:53 PM
  #9  
CFI-EFI's Avatar
CFI-EFI
Race Director
10 Year Member
 
Joined: Sep 2000
Posts: 17,298
Likes: 34
From: The Top of Utah
Default

Originally Posted by mudslide
THanks guys but im not haveing the same luck --the car still idles like crap after all that--runs good under power but not steady or at idle
What happens after you follow all the directions and suggestions listed in the "Symptoms" section of your FSM? Like those labeled, "hesitation, sag, stumble", "surges, and/or chuggle", "rough, unstable, or incorrect idle", "stalling", or "won't idle"?

RACE ON!!!
Reply
Old Apr 24, 2006 | 07:03 PM
  #10  
mudslide's Avatar
mudslide
Thread Starter
Racer
15 Year Member
 
Joined: Sep 2005
Posts: 385
Likes: 8
From: north branford ct
Default

Ill look again in the fsm but that thing is no better than the chiltons I have do this and do that but no explenations on how to do it. It is so much better to talk to someone on here who has done it and explans it so a moron like me can understand it--know what I mean?
Reply

Get notified of new replies

To throttle body cleaning





All times are GMT -4. The time now is 10:18 PM.

story-0
10 Corvettes to Drive Before You Die!

Slideshow: 10 Corvettes to drive before you die.

By Joe Kucinski | 2026-06-23 08:31:12


VIEW MORE
story-1
Corvette & Porsche 911: How Two Icons Conquered the Last 25 Years

Slideshow: Corvette and Porsche 911, how two icons conquered the last 25 years.

By Joe Kucinski | 2026-06-23 08:18:33


VIEW MORE
story-2
2027 Chevrolet Silverado 1500 First Look: Everything You NEED to Know!

Slideshow: Is the 2027 Chevrolet Silverado 1500 the best Silverado yet?

By Michael S. Palmer | 2026-06-16 08:01:12


VIEW MORE
story-3
5 Best & 5 Worst Corvette Daily Drivers

Slideshow: 5 best and 5 worst Corvette daily drivers

By Joe Kucinski | 2026-06-15 10:32:13


VIEW MORE
story-4
The Headlights of Every Corvette Generation Explained

Slideshow: The headlights of every Corvette generation explained

By Joe Kucinski | 2026-06-15 10:17:14


VIEW MORE
story-5
5 Best & 5 Most Overrated Corvette Track Packages of All Time!

Slideshow: The 5 best and 5 most overrated Corvette track packages ever.

By Joe Kucinski | 2026-06-09 12:46:45


VIEW MORE
story-6
Every 2027 Corvette Engine Explained

Slideshow: Every 2027 Corvette engine explained

By Joe Kucinski | 2026-06-09 12:16:31


VIEW MORE
story-7
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette

Slideshow: A Jaguar designer's personal project imagines what a modern front-engined Corvette might look like if Chevrolet revisited the golden age of the Stingray.

By Verdad Gallardo | 2026-06-08 19:53:43


VIEW MORE
story-8
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-9
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE