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

open loop

Thread Tools
 
Search this Thread
 
Old Apr 10, 2010 | 01:34 PM
  #1  
1986-z51's Avatar
1986-z51
Thread Starter
Instructor
 
Joined: Sep 2009
Posts: 110
Likes: 0
From: seabrook tx
Default open loop

Car wont go into closed loop. What are the requirments for closed loop? my temp is good,new 02 sensor.can run engine up to 2500 rpm still no closed loop.I have seen cars fall out of closed loop at idle,But this 1 wont go in at all. Have my own scanner,am able to look at all readings.Imput please. oh ya 1986 coup
Reply
Old Apr 10, 2010 | 08:56 PM
  #2  
RRT vette's Avatar
RRT vette
Le Mans Master
15 Year Member
 
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Default

Last time I scanned my 86, closed loop started when my engine temp was between 140-150*. The O2 sensor is the main determining factor for closed loop operation. The O2 sensor voltage will jump around consistanly when closed loop operation has been reached. The exhaust temp needs to be around 600* before the O2 sensor will become active.

Another sensor or circuitry that will prevent closed loop is the Coolant temperature sensor. Check to make sure your not getting any codes via scanning. If both of these sensors are working properly and you don't have a exhaust leak upstream on the driverside, you might want to swap in a different ECM or prom (86-89).
Reply
Old Apr 10, 2010 | 08:56 PM
  #3  
CorvetteMike2024's Avatar
CorvetteMike2024
Corvette Enthusiast
Supporting Lifetime Gold
15 Year Member
 
Joined: Oct 2007
Posts: 6,791
Likes: 2,697
From: So. Cal.
2025 C7 of the Year Finalist- Unmodified
2024 C7 of the Year Finalist - Unmodified
2023 C7 of the Year Finalist - Unmodified
Default

Originally Posted by 1986-z51
Car wont go into closed loop. What are the requirments for closed loop? my temp is good,new 02 sensor.can run engine up to 2500 rpm still no closed loop.I have seen cars fall out of closed loop at idle,But this 1 wont go in at all. Have my own scanner,am able to look at all readings.Imput please. oh ya 1986 coup
This book is a must read if you want to understand how your engine works. 311 pages


Reply
Old Apr 10, 2010 | 09:41 PM
  #4  
1986-z51's Avatar
1986-z51
Thread Starter
Instructor
 
Joined: Sep 2009
Posts: 110
Likes: 0
From: seabrook tx
Default

I got it to go into closed loop by taking the boocsh 02 sensor out an put in a delco. Been chasing a lean code,so i changed the 02 sensor.Now i found the 02 reading low like in the 200 range,an the blm on 160.Order a set of fuel injectors from john today.
Reply

Get notified of new replies

To open loop





All times are GMT -4. The time now is 04:16 AM.

story-0
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-1
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-2
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-3
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-4
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-5
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-6
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-7
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-8
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE
story-9
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE