Generation III External Engine LS1 | LS6 | Bolt-Ons | Intakes | Exhaust | Ignition | Accessories
Sponsored by:
Sponsored by:

3k idle after first start

Thread Tools
 
Search this Thread
 
Old May 27, 2009 | 10:59 AM
  #1  
Siphon's Avatar
Thread Starter
TECH Apprentice
iTrader: (7)
 
Joined: Mar 2005
Posts: 318
Likes: 0
From: Louisiana
Default 3k idle after first start

Recently, I removed my LS1 manifold, but had to reinstall it due to something that came up.

I plugged back in everything that I could find. Bolted down everything. Everything looks good to me. The only difference is that I have a new OPSU, and I ported my TB. Upon the first start, my car idled at 3k rpms. I let it idle for about 10 seconds before I shut her down. The battery was disconnected during the manifold swap.

Any ideas? Could this be a vacuum leak in the intake? Everything ran fine before, and the seals all looked good.
Reply
Old May 27, 2009 | 11:07 AM
  #2  
Stang's Bane's Avatar
TECH Addict
15 Year Member
iTrader: (22)
 
Joined: Aug 2005
Posts: 2,649
Likes: 1
From: Mont Belvieu, TX
Default

Originally Posted by Siphon
Recently, I removed my LS1 manifold, but had to reinstall it due to something that came up.

I plugged back in everything that I could find. Bolted down everything. Everything looks good to me. The only difference is that I have a new OPSU, and I ported my TB. Upon the first start, my car idled at 3k rpms. I let it idle for about 10 seconds before I shut her down. The battery was disconnected during the manifold swap.

Any ideas? Could this be a vacuum leak in the intake? Everything ran fine before, and the seals all looked good.
Yes it could be a vacuum leak. You are getting some unmetered air from some where.
Reply
Old May 27, 2009 | 11:09 AM
  #3  
Benner's Avatar
TECH Apprentice
iTrader: (2)
 
Joined: Nov 2007
Posts: 376
Likes: 0
From: Delaware, OH
Default

Could be overporting on the throttle body. Did you drill out the hole in the blade or knife edge the blade?
Reply
Old May 27, 2009 | 11:12 AM
  #4  
Siphon's Avatar
Thread Starter
TECH Apprentice
iTrader: (7)
 
Joined: Mar 2005
Posts: 318
Likes: 0
From: Louisiana
Default

I ported my throttle body well within reason. It could actually be ported a good bit more, but I didn't want to overstep the boundaries.
Reply
Old May 27, 2009 | 11:12 AM
  #5  
Siphon's Avatar
Thread Starter
TECH Apprentice
iTrader: (7)
 
Joined: Mar 2005
Posts: 318
Likes: 0
From: Louisiana
Default

Did not touch the TB blade at all.
Reply
Old May 27, 2009 | 11:14 AM
  #6  
Siphon's Avatar
Thread Starter
TECH Apprentice
iTrader: (7)
 
Joined: Mar 2005
Posts: 318
Likes: 0
From: Louisiana
Default

Originally Posted by Stang's Bane
Yes it could be a vacuum leak. You are getting some unmetered air from some where.
To remedy this...would I have to completely take off the intake manifold and reinstall? Or maybe just tighten some bolts more?

Also, I noticed, when I turn the key, I hear a small grinding that I never had before, from what I'm guessing is some sort of fuel line/pump related from under the hood.
Reply
Old May 27, 2009 | 11:20 AM
  #7  
Benner's Avatar
TECH Apprentice
iTrader: (2)
 
Joined: Nov 2007
Posts: 376
Likes: 0
From: Delaware, OH
Default

Originally Posted by Siphon
Did not touch the TB blade at all.
hmm. I had my idle just to 3200 rpm at one point but that was do to rediculously cold temperatures and a frozen Idle air control motor. you may try spraying some TB cleaner in the IAC vent to see if maybe it's stuck. No guarantee but hopefully it'd stop you from having to completely remove the manifold.
Reply
Old May 27, 2009 | 11:24 AM
  #8  
Siphon's Avatar
Thread Starter
TECH Apprentice
iTrader: (7)
 
Joined: Mar 2005
Posts: 318
Likes: 0
From: Louisiana
Default

This may be related, but I just noticed that my gauges move a lot faster when the car is turned on and off. They almost instantly go into their places.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

 Brett Foote
story-1

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-2

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-3

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-4

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-5

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-6

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-7

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-8

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-9

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
Old May 27, 2009 | 12:18 PM
  #9  
Siphon's Avatar
Thread Starter
TECH Apprentice
iTrader: (7)
 
Joined: Mar 2005
Posts: 318
Likes: 0
From: Louisiana
Default

Found the problem. The TB blade isn't closing completely. I started the car and forced it back, and it idled fine. Guess I'll have to find another TB. Thanks for the imput
Reply




All times are GMT -5. The time now is 07:12 AM.

story-0
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-09 14:55:56


VIEW MORE
story-1
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-2
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-3
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-4
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-5
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-6
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-7
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-8
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-9
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE