I there any possible reason for LEAVING the car in OPEN loop

Have a question or in need of assistance?
Post Reply
User avatar
geoffav
Second Lieutenant
Second Lieutenant
Posts: 362
Joined: Mon Jul 23, 2007 7:35 pm
Location: Enterprise, AL
Contact:

I there any possible reason for LEAVING the car in OPEN loop

Post by geoffav » Thu Nov 01, 2007 8:22 pm

I was reading a thread on another board today and a member of that board says his tuner has permanently "turned off" ALL 4 of his O2 sensors. The car is a street driven mildly modified 04 Mach1. He was sure that it was not forced open loop for tuning but tuned to forever run OL.

I've never heard of this and would think the efficiency offered by CL ops would be desirable. The reason given was the car could not be made to idle correctly with an Accufab TB installed.

Any thoughts on this......................
Geoff
04 Mach1 Torch Red 5spd w/281 CobraJet Engine
03 Mach1 Azure Blue 5spd w/281 CobraJet Engine
33 Ford 3 Window, 4.6DOHC stack intake

http://www.weevilcitycruisers.com/index.html

bgrd351
Command Sergeant Major
Command Sergeant Major
Posts: 107
Joined: Tue Jul 24, 2007 8:10 am

Re: I there any possible reason for LEAVING the car in OPEN loop

Post by bgrd351 » Fri Nov 02, 2007 6:47 am

three things...

1. didnt know you could turn off the 2 front O2's

2. turn off adaptive and it is about the same thing I do believe

3. why would anyone WANT to tune a EFI car like a carb?? why lose all the good stuff of EFI....hmmmmm?

User avatar
geoffav
Second Lieutenant
Second Lieutenant
Posts: 362
Joined: Mon Jul 23, 2007 7:35 pm
Location: Enterprise, AL
Contact:

Re: I there any possible reason for LEAVING the car in OPEN loop

Post by geoffav » Fri Nov 02, 2007 4:29 pm

bgrd351 wrote:three things...

1. didnt know you could turn off the 2 front O2's

2. turn off adaptive and it is about the same thing I do believe

3. why would anyone WANT to tune a EFI car like a carb?? why lose all the good stuff of EFI....hmmmmm?
I agree it don't make much sense to me. After reading some later posts to the thread I mention above ---- I'm even more confused. :lol:
Geoff
04 Mach1 Torch Red 5spd w/281 CobraJet Engine
03 Mach1 Azure Blue 5spd w/281 CobraJet Engine
33 Ford 3 Window, 4.6DOHC stack intake

http://www.weevilcitycruisers.com/index.html

Mattr66
Warrant Officer 5
Warrant Officer 5
Posts: 292
Joined: Fri Jul 20, 2007 4:58 pm
Location: College Station, TX

Re: I there any possible reason for LEAVING the car in OPEN loop

Post by Mattr66 » Sat Nov 03, 2007 12:28 am

A few reasons to run open loop:

really wild overlap that makes the fuel trims go goofy at low RPMS.

long tube headers that let the o2 sensors get too cold at low loads and start adding too much fuel.

wanting leaner than 14.7:1 at cruise.

wanting progressive richening of the mixture from cruise to WOT (some forms of racing use this to run the cars cooler at mid throttle and saving fuel over just keeping the car at it's WOT mixture at mid throttle).

... that's all I can think of right now

Matt R
Matt Robinson
Delta Force Gas and Diesel Tuner
www.gearheadautomotiveperformance.com

User avatar
geoffav
Second Lieutenant
Second Lieutenant
Posts: 362
Joined: Mon Jul 23, 2007 7:35 pm
Location: Enterprise, AL
Contact:

Re: I there any possible reason for LEAVING the car in OPEN loop

Post by geoffav » Sun Nov 04, 2007 1:42 am

It would seem the tuner (according to the car owner) went OL because the car had bad o2 sensors and it would save the owner $200ish. This is a street driven car with mostly drivetrain mods. I don't get it. :o
Geoff
04 Mach1 Torch Red 5spd w/281 CobraJet Engine
03 Mach1 Azure Blue 5spd w/281 CobraJet Engine
33 Ford 3 Window, 4.6DOHC stack intake

http://www.weevilcitycruisers.com/index.html

Post Reply

Return to “Commando - Delta Forces Help”