Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums - Camaro5.com
 
sjm autoprod
Go Back   Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums - Camaro5.com > Engine | Drivetrain | Powertrain Technical Discussions > Forced Induction - V8


Reply
 
Thread Tools
Old 01-15-2011, 07:37 AM   #743
Huggerorange73
Banned
 
Drives: The REAL C5
Join Date: Nov 2007
Location: Norridge, IL
Posts: 1,830
Send a message via AIM to Huggerorange73
Quote:
Originally Posted by zebra View Post
i have trouble believing this car would be in closed loop withing 1 minute of a cold start when it's 20* outside
Damn, you guys made me drag out all my notes and books from my classes I took

When a car is started, the computer is in open loop until certain criteria is met. The o2 sensors need to be heated to work properly, so this is the main reason there is a delay.

After the sensors are heated up, the car goes into closed loop and the O2 sensors make their corrections.

The computer will go back into open loop under a variety of conditions. Throttle Position (TP) is one way.

There are parameters in the computer that determine what the TP is for Open Loop, and other things.

When that TP is reached, and the car goes open loop, and richens up.


In closed loop fueling, the computer takes readings from the oxygen sensors which read +/- of 14.64 AFR (Stoich) and makes corrections for it. If your car is idling @ 13.5 AFR, the 02s can see this, and will know to pull out enough fuel to get back to stoich.

In open loop, the fueling is purely based off the MAF transfer function and the open loop fuel table. This table has to be calibrated any time you make MAF changes, and changes that affect the airflow of the MAF.

With that being said.....as long as the 02 sensors are warm, he's in the loop..given the fact they are heated, it's likely the car is in fact in closed loop.
Huggerorange73 is offline   Reply With Quote
Old 01-15-2011, 07:50 AM   #744
Scott@Bjorn3D


 
Scott@Bjorn3D's Avatar
 
Drives: Kami, 2013 2SS LS3 Luvin
Join Date: Oct 2008
Location: Eufaula, Alabama
Posts: 6,353
Send a message via MSN to Scott@Bjorn3D
But he is running CAT Less. The sensors are not reading anything.
Scott@Bjorn3D is offline   Reply With Quote
Old 01-15-2011, 08:06 AM   #745
Huggerorange73
Banned
 
Drives: The REAL C5
Join Date: Nov 2007
Location: Norridge, IL
Posts: 1,830
Send a message via AIM to Huggerorange73
Quote:
Originally Posted by Scott@Bjorn3D View Post
But he is running CAT Less. The sensors are not reading anything.

That is incorrect....there are 2 sets of 02 sensors on the car, one set before the cats ( which will be in the collector of the header ) and one post cat ( in the cat or the off road pipe ).

The rear 02 sensor are disabled in the PCM so they don't throw codes...the front 2 are still sending info the PCM to determine A/F ratio.
Huggerorange73 is offline   Reply With Quote
Old 01-15-2011, 09:08 AM   #746
Scott@Bjorn3D


 
Scott@Bjorn3D's Avatar
 
Drives: Kami, 2013 2SS LS3 Luvin
Join Date: Oct 2008
Location: Eufaula, Alabama
Posts: 6,353
Send a message via MSN to Scott@Bjorn3D
He told me he did not hook anything to the headers. Made it sound like the cables and sensors are just tied up on his car in a loop.
Scott@Bjorn3D is offline   Reply With Quote
Old 01-15-2011, 09:12 AM   #747
BackinBlackSS/RS
Go Blue!!!!!
 
BackinBlackSS/RS's Avatar
 
Drives: 2012 Cruze LT
Join Date: Mar 2009
Location: Indiana
Posts: 23,297
Quote:
Originally Posted by Scott@Bjorn3D View Post
He told me he did not hook anything to the headers. Made it sound like the cables and sensors are just tied up on his car in a loop.
He would have to have the collector 02 sensors or his car would be even more screwed up than it is now.
BackinBlackSS/RS is offline   Reply With Quote
Old 01-15-2011, 09:12 AM   #748
BlownSS

 
BlownSS's Avatar
 
Drives: 2010 Camaro SS/RS
Join Date: Oct 2009
Location: Lincoln Nebraska
Posts: 1,758
Quote:
Originally Posted by Scott@Bjorn3D View Post
Make Peace with Ted. Order CNC VMAX from Ted since Chris just bought one and buy a tune from Ted and be done with it. Ted could probably have you running today if you would listen to me. 300.00 from Ted and your tranny will be freaking tuned also. You should really quit being so pig headed at times.

Shit did i really just type that?
Sometimes when you buy stuff from ted, he will give you a free tune!!!!! Maybe give him a call and see what he has to get you going......kinda like buying a tune and getting a free toy!
__________________
2010 IOM SS/RS LS3, Hennessey HPE550 Polished Magnuson TVS2300 Supercharger. 3.4 Pulley. Kooks long tube headers / high flow cats. GHL Full exhaust. ZL1 Fuel Pump/ADM FPCM. MSW Bap. JRE ZL1 Race cam with new springs/pushrods/Trunion Upgrade. FIC 850cc injectors. ZR1 Map sensor. CAI Induction. JRE Tune.
BlownSS is offline   Reply With Quote
Old 01-15-2011, 09:21 AM   #749
Russell James


 
Russell James's Avatar
 
Drives: '69 Drag, #37 TA Stock Car, '15 ILE
Join Date: Dec 2009
Location: SE Michigan
Posts: 3,733
Before running much more, I'd check the oil. Make sure the oil doesn't smell like gas. Just to make sure it's not way overfueling and washing down the cylinders. You can get a rough idea if the stall is from rich or lean by blipping the throttle while its starting to die. If it chugs, revs real slow, and puffs out dark smoke.... way too rich. If it stumbles, hesitates, pops, revs quick, no dark smoke, no gas odor, then way too lean.

A few more run times (as long as it's not flooding the oil with gas) should be enough to set a code. If the oil is good, I'd give it a few more warm up runs, check the data and codes. If it's not setting codes, maybe it is just the tune. But normally it takes quite a significant mechanical change to a motor such as a big cam to not even be able to stay running on the stock tune. Fuel pressure should be fine if it idles good in open loop.

The O2 readings, short term fuel trim, when the problem is happening should tell the story.
Russell James is offline   Reply With Quote
Old 01-15-2011, 09:52 AM   #750
Huggerorange73
Banned
 
Drives: The REAL C5
Join Date: Nov 2007
Location: Norridge, IL
Posts: 1,830
Send a message via AIM to Huggerorange73
Quote:
Originally Posted by Scott@Bjorn3D View Post
He told me he did not hook anything to the headers. Made it sound like the cables and sensors are just tied up on his car in a loop.
If that's the case....he's got some serious issues on his hands.
Huggerorange73 is offline   Reply With Quote
Old 01-15-2011, 10:12 AM   #751
PQ
Booooosted.
 
PQ's Avatar
 
Drives: 2010 Supercharged SS
Join Date: Apr 2008
Location: Mobile, AL
Posts: 36,718
Send a message via Yahoo to PQ
Quote:
Originally Posted by Scott@Bjorn3D View Post
Make Peace with Ted. Order CNC VMAX from Ted since Chris just bought one and buy a tune from Ted and be done with it. Ted could probably have you running today if you would listen to me. 300.00 from Ted and your tranny will be freaking tuned also. You should really quit being so pig headed at times.

Shit did i really just type that?
I don't need a VMAX. And no mail order tune will ever get the max efficiency as a dyno tune. It's not Ted. There is no need to 'make peace'. It's not Ted himself that makes me not buy a tune. It's just that I don't believe he can do what I need.

Quote:
Originally Posted by wkdivr View Post
I would tend to agree. Do what's needed to get a tune from somebody as reputable as Janetty. Then after your other mods ( don't worry, there'll be more!!!) you can send him your logs, and he can adjust accordingly.
I don't like sendign stuff and not knowing when I'm gonna get taken care of. The thought of sendign an emial, waiting to hear back, sending another, waiting again, to get 'close' to a good tune is not appealing at all. I don't even know how to do the data logs.

Quote:
Originally Posted by Scott@Bjorn3D View Post
He told me he did not hook anything to the headers. Made it sound like the cables and sensors are just tied up on his car in a loop.
You got me mixed up with someone else.

All of my sensors are plugged in.

Quote:
Originally Posted by Huggerorange73 View Post
That is incorrect....there are 2 sets of 02 sensors on the car, one set before the cats ( which will be in the collector of the header ) and one post cat ( in the cat or the off road pipe ).

The rear 02 sensor are disabled in the PCM so they don't throw codes...the front 2 are still sending info the PCM to determine A/F ratio.
I totaly forgot about that. So it could explain too why even the stock tune is messing up.

Quote:
Originally Posted by Russell James View Post
Before running much more, I'd check the oil. Make sure the oil doesn't smell like gas. Just to make sure it's not way overfueling and washing down the cylinders. You can get a rough idea if the stall is from rich or lean by blipping the throttle while its starting to die. If it chugs, revs real slow, and puffs out dark smoke.... way too rich. If it stumbles, hesitates, pops, revs quick, no dark smoke, no gas odor, then way too lean.

A few more run times (as long as it's not flooding the oil with gas) should be enough to set a code. If the oil is good, I'd give it a few more warm up runs, check the data and codes. If it's not setting codes, maybe it is just the tune. But normally it takes quite a significant mechanical change to a motor such as a big cam to not even be able to stay running on the stock tune. Fuel pressure should be fine if it idles good in open loop.

The O2 readings, short term fuel trim, when the problem is happening should tell the story.


Quote:
Originally Posted by Huggerorange73 View Post
If that's the case....he's got some serious issues on his hands.
Everythings plugged in.
__________________
PQ is offline   Reply With Quote
Old 01-15-2011, 11:24 AM   #752
Russell James


 
Russell James's Avatar
 
Drives: '69 Drag, #37 TA Stock Car, '15 ILE
Join Date: Dec 2009
Location: SE Michigan
Posts: 3,733
One quick check you can do to make sure all the pcv stuff is hooked up right... While it is idling relatively stable, take the oil cap off real quick. The engine should falter slightly and a small drop in rpm. Stick it back on and it should stabilize. It is very slight but noticeable. If there is absolutely no change when popping the oil cap on and off at idle, something in the PCV is not right or vacuum leak somewhere.
Russell James is offline   Reply With Quote
Old 01-15-2011, 11:30 AM   #753
PQ
Booooosted.
 
PQ's Avatar
 
Drives: 2010 Supercharged SS
Join Date: Apr 2008
Location: Mobile, AL
Posts: 36,718
Send a message via Yahoo to PQ
Quote:
Originally Posted by Russell James View Post
One quick check you can do to make sure all the pcv stuff is hooked up right... While it is idling relatively stable, take the oil cap off real quick. The engine should falter slightly and a small drop in rpm. Stick it back on and it should stabilize. It is very slight but noticeable. If there is absolutely no change when popping the oil cap on and off at idle, something in the PCV is not right or vacuum leak somewhere.
I'll try it.
__________________
PQ is offline   Reply With Quote
Old 01-15-2011, 11:42 AM   #754
mlee
Charter Circle Member
 
mlee's Avatar
 
Drives: Number Twenty-Three
Join Date: Oct 2008
Location: Conroe, TX
Posts: 27,698
Quote:
Originally Posted by Huggerorange73 View Post
My guess is it's coming into closed loop at that point...at that time, it's taking info from all the sensors to make it's call on fuel & spark.
Quote:
Originally Posted by Huggerorange73 View Post
When a car is started, the computer is in open loop until certain criteria is met. The o2 sensors need to be heated to work properly, so this is the main reason there is a delay.

After the sensors are heated up, the car goes into closed loop and the O2 sensors make their corrections.

The computer will go back into open loop under a variety of conditions. Throttle Position (TP) is one way.

There are parameters in the computer that determine what the TP is for Open Loop, and other things.

When that TP is reached, and the car goes open loop, and richens up.


In closed loop fueling, the computer takes readings from the oxygen sensors which read +/- of 14.64 AFR (Stoich) and makes corrections for it. If your car is idling @ 13.5 AFR, the 02s can see this, and will know to pull out enough fuel to get back to stoich.

In open loop, the fueling is purely based off the MAF transfer function and the open loop fuel table. This table has to be calibrated any time you make MAF changes, and changes that affect the airflow of the MAF.

With that being said.....as long as the 02 sensors are warm, he's in the loop..given the fact they are heated, it's likely the car is in fact in closed loop.


I believe if left at idle the time is an 88 sec delay which coincides w/ shutdown in the video...
__________________
.
mlee is offline   Reply With Quote
Old 01-15-2011, 08:12 PM   #755
Darth_Emma
Psssssssssshhhhhhhhhhhhh!
 
Darth_Emma's Avatar
 
Drives: under contruction
Join Date: Nov 2009
Location: Marysville, Ohio
Posts: 13,149
Mighty quiet in here. I can hear crickets.
__________________
Darth_Emma is offline   Reply With Quote
Old 01-15-2011, 08:15 PM   #756
BackinBlackSS/RS
Go Blue!!!!!
 
BackinBlackSS/RS's Avatar
 
Drives: 2012 Cruze LT
Join Date: Mar 2009
Location: Indiana
Posts: 23,297
Quote:
Originally Posted by Darth_Emma View Post
Mighty quiet in here. I can hear crickets.
BackinBlackSS/RS is offline   Reply With Quote
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Where to get engine cover modified after a Maggie install? 1meanss Cosmetics and Lighting Modification Discussions 5 03-05-2011 09:00 PM
Another Maggie install .... Luvpilot Forced Induction - V8 9 06-20-2010 09:00 PM
maggie install, hose routing suggestions please n2oSS Forced Induction - V8 6 05-31-2010 03:59 PM
DIY : Install catback on 2010 Camaro SS Nine Ball Camaro DIY & HOW-TO instructions & discussions 3 08-09-2009 04:36 PM


All times are GMT -5. The time now is 02:24 PM.


Powered by vBulletin® Version 3.8.9 Beta 4
Copyright ©2000 - 2016, vBulletin Solutions, Inc.