Generation III Internal Engine 1997-2006 LS1 | LS6
Sponsored by:
Sponsored by:

Valve float?

Thread Tools
 
Search this Thread
 
Old Nov 2, 2008 | 09:39 AM
  #1  
2001z's Avatar
Thread Starter
Banned
iTrader: (32)
 
Joined: Mar 2005
Posts: 1,157
Likes: 0
From: Fountain Inn, SC
Default Valve float?

ok guys went on the dyno last week and had a problem when i sprayed a 150 shot. It seemed perfect till i got up to 5900-6800 and the car fell flat on its face and a/f went lean twice in a row. The injectors were at 95% . I have prc duals in there so not sure what to do to fix this problem?? what can i do to get this issue resolved. could it be the rockers to tight? stock rockers to and stock heads. Also one other thing it didnt do it on motor just on spray and it was right at the 6k area.

Last edited by 2001z; Nov 2, 2008 at 10:02 AM.
Reply
Old Nov 2, 2008 | 02:59 PM
  #2  
LS1-450's Avatar
TECH Junkie
iTrader: (33)
 
Joined: Aug 2005
Posts: 3,783
Likes: 9
Default

Running out of injector or fuel pressure. Rule of thumb is 80% injector duty max. You need a wet 150 shot or bigger injectors. If you have a wet shot, then you're losing fuel pressure.
Reply
Old Nov 2, 2008 | 07:06 PM
  #3  
2001z's Avatar
Thread Starter
Banned
iTrader: (32)
 
Joined: Mar 2005
Posts: 1,157
Likes: 0
From: Fountain Inn, SC
Default

Originally Posted by LS1-450
Running out of injector or fuel pressure. Rule of thumb is 80% injector duty max. You need a wet 150 shot or bigger injectors. If you have a wet shot, then you're losing fuel pressure.
It has to be the injector becouse i know im getting no lower than 57lbs at wott at 6k and up at my fuel rail. I was spraying a 150 wett
Reply
Old Nov 2, 2008 | 07:28 PM
  #4  
LS1-450's Avatar
TECH Junkie
iTrader: (33)
 
Joined: Aug 2005
Posts: 3,783
Likes: 9
Default

By injector you mean the nitrous fuel injector, right? If you're 57 PSI & @ 95% on the stock injectors, then I would agree that there is an issue w/ the nitrous fuel injector or the plumbing to the nitrous fuel injector.

EDIT: or the electronics/control of the nitrous fuel injector
Reply
Old Nov 3, 2008 | 05:49 AM
  #5  
2001z's Avatar
Thread Starter
Banned
iTrader: (32)
 
Joined: Mar 2005
Posts: 1,157
Likes: 0
From: Fountain Inn, SC
Default

Originally Posted by LS1-450
By injector you mean the nitrous fuel injector, right? If you're 57 PSI & @ 95% on the stock injectors, then I would agree that there is an issue w/ the nitrous fuel injector or the plumbing to the nitrous fuel injector.

EDIT: or the electronics/control of the nitrous fuel injector
Not sure what you mean by nitrous fuel injector i was meaning 95% duty cycle on the cars injectors im not sure what a nitrous injector is enless you mean nozzle? It was fine up till high rpms like 5800-6k and it took a nose dive. I talked to the guy at the dyno and he said it didnt look like valve float by looking at the dyno runs but im not sure. I dont have a fpss switch either to cause it to cut out.
Reply
Old Nov 3, 2008 | 05:54 AM
  #6  
LS1-450's Avatar
TECH Junkie
iTrader: (33)
 
Joined: Aug 2005
Posts: 3,783
Likes: 9
Default

Originally Posted by 2001z
Not sure what you mean by nitrous fuel injector i was meaning 95% duty cycle on the cars injectors im not sure what a nitrous injector is enless you mean nozzle? It was fine up till high rpms like 5800-6k and it took a nose dive. I talked to the guy at the dyno and he said it didnt look like valve float by looking at the dyno runs but im not sure. I dont have a fpss switch either to cause it to cut out.

You said it was a wet shot. A wet shot means that the nitrous system adds fuel to the nitrous w/ added injector or injectors that come with the kit. So, if your nitrous kit did not come with a fuel set up, then you are spraying a dry shot which is overloading your cars' injectors. It's not valve float.

Fuel needs to be added either by larger (car) injectors or a wet nitrous kit.
Reply
Old Nov 3, 2008 | 11:36 AM
  #7  
2001z's Avatar
Thread Starter
Banned
iTrader: (32)
 
Joined: Mar 2005
Posts: 1,157
Likes: 0
From: Fountain Inn, SC
Default

Originally Posted by LS1-450
You said it was a wet shot. A wet shot means that the nitrous system adds fuel to the nitrous w/ added injector or injectors that come with the kit. So, if your nitrous kit did not come with a fuel set up, then you are spraying a dry shot which is overloading your cars' injectors. It's not valve float.

Fuel needs to be added either by larger (car) injectors or a wet nitrous kit.
Umm lol i know how a wett shot works been spraying for years. Just never heard someone call a fuel noid a injector. Im actually going to buy 2 new noids to see if the fuel noid is just failing me or closing off.
Reply
Old Nov 3, 2008 | 12:22 PM
  #8  
03_r6's Avatar
Staging Lane
 
Joined: Sep 2007
Posts: 90
Likes: 0
From: manhattan, KS
Default

if you had your fuel noid fail i would think that that it would only happen once, and make a big kaboom shortly after. I would upgrade the injectors, 95% DC is simply too much. Also i doubt your fuel noid is failing as much as your fuel pump is failing. Replace the pump and the injectors and you should be set to hit the kit all day long.

Last edited by 03_r6; Nov 3, 2008 at 12:27 PM.
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 Nov 3, 2008 | 03:29 PM
  #9  
LS1-450's Avatar
TECH Junkie
iTrader: (33)
 
Joined: Aug 2005
Posts: 3,783
Likes: 9
Default

Originally Posted by 2001z
Umm lol i know how a wett shot works been spraying for years. Just never heard someone call a fuel noid a injector. Im actually going to buy 2 new noids to see if the fuel noid is just failing me or closing off.
Then you outta know better than to think 95% duty cycle on stock injectors is valve float.

As to the suggestion that you need injectors & a fuel pump; you already confirmed 57 psi during WOT & that the car is not lean during WOT on motor only. So, if it's not lean on motor & injectors are only 95% while spraying, then it's the wet shot kit related fueling, either mechanical or electrical.
Reply
Old Nov 3, 2008 | 04:34 PM
  #10  
2001z's Avatar
Thread Starter
Banned
iTrader: (32)
 
Joined: Mar 2005
Posts: 1,157
Likes: 0
From: Fountain Inn, SC
Default

Originally Posted by 03_r6
if you had your fuel noid fail i would think that that it would only happen once, and make a big kaboom shortly after. I would upgrade the injectors, 95% DC is simply too much. Also i doubt your fuel noid is failing as much as your fuel pump is failing. Replace the pump and the injectors and you should be set to hit the kit all day long.
Fuel pump is fine its a racetronix with hotwire , I had a nitrous backfire on the dyno shortly after that run leaving me to believe the problem migh be noid/nitrous issues. My understanding stock injectors can run over 100% with no problem.
Reply




All times are GMT -5. The time now is 06:29 PM.

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