Factory O2s off, commanded A/F, ect...
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From: Port Tobacco, MD
Factory O2s off, commanded A/F, ect... Just a couple of things, did some tuning today and once I turned the factory O2s back on I saw that they wanted to correct to 14.4 instead of 14.7 on my LM1. Is there any way to way to make them correct to 14.7? I have a tendency to believe the LM1 vs the factory O2s.
I did the normal SD tune and when you turn the O2s back on you lose your smooth A/F transision that is programmed into the open loop EQ table(1.0 -> 1.13 ect). Is there a way to get the smooth transition back under closed loop like open loop?
I did the normal SD tune and when you turn the O2s back on you lose your smooth A/F transision that is programmed into the open loop EQ table(1.0 -> 1.13 ect). Is there a way to get the smooth transition back under closed loop like open loop?
Try dropping your O2 switch points 50~100mV.
As for the transition, I would set all of open loop, operating temp AFR's to stoich and let PE come on as if it did in closed loop when I was tuning. To answer your question though...aside from going with a custom operating system running semi-closed loop, no. PE is either on or off.
As for the transition, I would set all of open loop, operating temp AFR's to stoich and let PE come on as if it did in closed loop when I was tuning. To answer your question though...aside from going with a custom operating system running semi-closed loop, no. PE is either on or off.
The O2's provide feedback around part throttle, where the PCM is commanding a 14.63:1 AFR. This feedback allows the PCM to "learn" optimal day-to-day fueling through the fuel trims. These learnings then become assumptions at WOT when positive fuel trims are added on top of know WOT fueling requirements. You turn the O2's off and your car behaves like a carburated setup - it is what it is and there's no self-adjustment. The upside? Well, if you want to think of it that way, one upside is you won't have any positive trims interfering with your WOT AFR. The downers...you're car won't learn, it could run pretty lean at times, inconsistent/worse gas mileage, etc.
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From: Port Tobacco, MD
Here is why I like OLSD:
You can start adding fuel @ 75kpa in a linear fashion to 105kpa
This allows you to add 2-6 degrees of more timing in that area making more power under the curve
When you run closed loop its either 14.7 or PE, no inbetween.
Phil
You can start adding fuel @ 75kpa in a linear fashion to 105kpa
This allows you to add 2-6 degrees of more timing in that area making more power under the curve
When you run closed loop its either 14.7 or PE, no inbetween.
Phil
Totally off topic, but when interfacing the MPVI Pro with the LM1 all you use is two wires from the Lm1 right (one ground and one analog input)? So from there where can you see the readings? I am a newbiew trying to learn how to tune this dame car!
Also do you guys think it is neccesary to put my IAC back on? I will be using a 105mm Accufab and I know there is some modifications that need to be done to run it. How will tunning be with and without it?
Will my MAP readings get thrown off if I T off my sensor from the brake boster line in the back of the intake (BECK) or is the pressure pretty constant through out the system?
Also do you guys think it is neccesary to put my IAC back on? I will be using a 105mm Accufab and I know there is some modifications that need to be done to run it. How will tunning be with and without it?
Will my MAP readings get thrown off if I T off my sensor from the brake boster line in the back of the intake (BECK) or is the pressure pretty constant through out the system?
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From: Port Tobacco, MD
I just use the one signal wire from the LM1. I log a startup file with the car not running and record the LM1 and the HPT. I download the software and compare. If the LM1 is higher than HPT or vice versa I correct until the HPT 100% matches the LM1. Usually there is a .3 difference or so.
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Thread Starter
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From: Port Tobacco, MD
I will bet that the LM1 is off. It may be a ground thing. You can check it out with an ohm meter. The factory O2 will switch at 14.6. Do you see the factory one swith up and down?