TBI Throttle Body Injection discussion and questions. L03/CFI tech and other performance enhancements.

Adjusting Idle

Thread Tools
 
Search this Thread
 
Old Jan 11, 2008 | 11:18 AM
  #1  
robster66's Avatar
Thread Starter
Senior Member
iTrader: (1)
 
Joined: Oct 2007
Posts: 280
Likes: 0
From: Glen Mills, PA
Car: 1992 Chevrolet Camaro RS
Engine: 305 T.B.I.
Transmission: 700R4
Axle/Gears: 2.73 Open Diff
Adjusting Idle

How do I adjust the idle on a TBI carb? It seems pretty high around 1.3k
Reply
Old Jan 11, 2008 | 01:51 PM
  #2  
Ronny's Avatar
TGO Supporter
20 Year Member
iTrader: (1)
 
Joined: Mar 2003
Posts: 6,880
Likes: 4
From: wisconsin
Re: Adjusting Idle

TBI or Carb. TBI is really not adjustable. RPM is set in chip aka .bin. Maybe a vac leak. Or slop at butterfly shaft allowing air to enter.
Reply
Old Jan 13, 2008 | 07:58 PM
  #3  
Brandon2350's Avatar
Member
20 Year Member
 
Joined: Feb 2003
Posts: 168
Likes: 0
From: Winslow, Maine
Car: 1993 Z-71 pickup
Engine: Heavily modified 355 on TBI
Transmission: Had a 4L60e. Now a 700R4
Axle/Gears: Bone Stock
Re: Adjusting Idle

What is it specifically that your trying to do? Are you trying to raise or lower your idle and why. If you can give some specific details we may be able to help you better.

Brandon
Reply
Old Jan 14, 2008 | 11:33 PM
  #4  
MarkAJ86's Avatar
Member
 
Joined: May 2007
Posts: 167
Likes: 0
From: Buffalo
Car: 1984 Chevrolet Camaro Z28
Engine: 305tbi
Transmission: 700R4
Re: Adjusting Idle

Seeing as he said its high at 1300rpms i think he wants to lower it.
Reply
Old Jan 15, 2008 | 12:51 PM
  #5  
Jason89RS's Avatar
Member
20 Year Member
iTrader: (2)
 
Joined: Jan 2005
Posts: 399
Likes: 1
From: Yucaipa, CA
Re: Adjusting Idle

Yes there is a way to adjust your RPM's on a TBI, but I would first look at if you have a vacuum leak, increased base timing or the IAC needs to be adjusted, cleaned or replaced which may be causing he high idle. To adjust the idle you'll need to find aluminum plug on the front of the TBI by the throttle linkage. Remove this plug. Behind that is a screw (most likely torx) that you can use to adjust you're idle speed. You'll want to use an external tach rather than the one that's in the car.

Last edited by Jason89RS; Jan 17, 2008 at 10:19 AM.
Reply
Old Jan 16, 2008 | 09:04 PM
  #6  
Brandon2350's Avatar
Member
20 Year Member
 
Joined: Feb 2003
Posts: 168
Likes: 0
From: Winslow, Maine
Car: 1993 Z-71 pickup
Engine: Heavily modified 355 on TBI
Transmission: Had a 4L60e. Now a 700R4
Axle/Gears: Bone Stock
Re: Adjusting Idle

If your setup was ok and you changed nothing but it started idleing up higher, you definately dont want to remove that aluminum plug and attempt to lower your idle. This is usually done by experienced tuners when you have changed the airflow charestics of the motor. Changing this will definately change a lot more than your idle.

Check the items from the member above that he mentioned before even thinking about popping the plug.
Reply
Old Jan 17, 2008 | 09:20 AM
  #7  
Ronny's Avatar
TGO Supporter
20 Year Member
iTrader: (1)
 
Joined: Mar 2003
Posts: 6,880
Likes: 4
From: wisconsin
Re: Adjusting Idle

Look at IAC pindle to determine if it is working or very dirty. Key on engine off it should move. Check your hoses to TBI for a vac leak.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
GeneralIesrussi
Carburetors
6
Jun 20, 2024 07:21 PM
db057
TBI
14
Apr 28, 2019 07:45 AM
IROCtometal
TPI
2
Sep 20, 2015 11:08 PM
IROCtometal
TPI
3
Sep 9, 2015 10:01 AM
IROCtometal
TPI
0
Sep 2, 2015 02:01 PM




All times are GMT -5. The time now is 09:43 AM.