O2s Don't Lock At WOT
Thread Starter
Joined: Nov 2001
Posts: 5,649
Likes: 9
From: Warr Acres, OK
O2s Don't Lock At WOT What would cause O2s to start out really low, then continue to oscillate at WOT? Vehicle is a 02 6L Truck. First log after small cam (221/.559 112) install still on stock tune. No other mods other than no cats.
Fuel trim in the cells prior to WOT being positive (showing a lean) condition will cause this. VE tuning will take care of it, quick dirty way is to go and adjust the VE at those points, but not the correct way to handle it.
It looks to me like you are not in PE / open loop
despite a 100% indicated TPS.
Check the PE enable settings (MAP, TPS), the
PE mode delay value and RPM threshold. I think
something is locking you out of PE.
despite a 100% indicated TPS.
Check the PE enable settings (MAP, TPS), the
PE mode delay value and RPM threshold. I think
something is locking you out of PE.
TECH Enthusiast
Joined: Mar 2003
Posts: 618
Likes: 0
From: San Diego
Agreed. Even if you carry a positve fuel trim modifier into WOT, you'll still go into open loop.
Originally Posted by jimmyblue
It looks to me like you are not in PE / open loop
despite a 100% indicated TPS.
Check the PE enable settings (MAP, TPS), the
PE mode delay value and RPM threshold. I think
something is locking you out of PE.
despite a 100% indicated TPS.
Check the PE enable settings (MAP, TPS), the
PE mode delay value and RPM threshold. I think
something is locking you out of PE.
Originally Posted by jimmyblue
It looks to me like you are not in PE / open loop
despite a 100% indicated TPS.
Check the PE enable settings (MAP, TPS), the
PE mode delay value and RPM threshold. I think
something is locking you out of PE.
despite a 100% indicated TPS.
Check the PE enable settings (MAP, TPS), the
PE mode delay value and RPM threshold. I think
something is locking you out of PE.
easy way to check would setup a status bit or at least see your IPW's The truck has permission to try and tune for the commanded air fuel ratio that is commanded.
That being said, They have shut off Pe mode, If you look at your pe mode delay times and rpm, you will see.
That being said, They have shut off Pe mode, If you look at your pe mode delay times and rpm, you will see.
Thread Starter
Joined: Nov 2001
Posts: 5,649
Likes: 9
From: Warr Acres, OK
These are the settings in the PCM when I did the log. I had made some edits but nothing I considered tuning yet.
PE Mode Enable Hot and Cold Tables - All cells 90% (stock setting)
Hot/Cold table Thresh - 284 (irrelevent since both tables are the same.)
PE Enable Map - 55Kpa (stock setting)
PE Mode Delay RPM - 2000 (stock setting was 5500) (HPTuners says this is ignored on car calibrations. Does anyone know FOR SURE if it is used on trucks?)
PE Mode Map Hyst - 6
COT - Off
EQ Ratio - All cells stock values.
PE Mode Enable Hot and Cold Tables - All cells 90% (stock setting)
Hot/Cold table Thresh - 284 (irrelevent since both tables are the same.)
PE Enable Map - 55Kpa (stock setting)
PE Mode Delay RPM - 2000 (stock setting was 5500) (HPTuners says this is ignored on car calibrations. Does anyone know FOR SURE if it is used on trucks?)
PE Mode Map Hyst - 6
COT - Off
EQ Ratio - All cells stock values.
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Verdad Gallardo Thread Starter
Joined: Nov 2001
Posts: 5,649
Likes: 9
From: Warr Acres, OK
On a different truck (03 5.3L) I've logged on a dyno, with it's PE Delay RPM set at 5000, it clearly went into OL PE mode at 2800~3000 on 5 different pulls. That is why I question it's use on trucks. Do you agree it's not used on cars? That truck's calibration also had a PE Delay Time paramater set at 2 sec, and it looked like that was delaying it about 2 sec on the log. The 02 6.0L cal I'm working with here does not show that time delay parameter available to me with what I'm using to edit. I'm only using HPT to log trucks, not to edit them. I have a few other PE paramaters available to me.
PE Corr Step Size - 0.020
PE Corr Apply Rate - .05 sec/step
PR Corr Remove Rate - .05 sec/step
Max Alowable Enrichment - 1.400 mult
On the log in question, the truck was at 100% TPS for 10 seconds so I think any time delay should have meen met.
PE Corr Step Size - 0.020
PE Corr Apply Rate - .05 sec/step
PR Corr Remove Rate - .05 sec/step
Max Alowable Enrichment - 1.400 mult
On the log in question, the truck was at 100% TPS for 10 seconds so I think any time delay should have meen met.
"Hey, Bob, let's make this one ping like a MF for
about a minute every time, just for giggles"?
Once that gets right, then you can see how crazy
low the timing tables are. And how pointless /
oversensitive the burst knock setup is.
about a minute every time, just for giggles"?
Once that gets right, then you can see how crazy
low the timing tables are. And how pointless /
oversensitive the burst knock setup is.
Thread Starter
Joined: Nov 2001
Posts: 5,649
Likes: 9
From: Warr Acres, OK
I can understand low timing tables and sensitive KR since they are tuned for 87 octane gas, but any delay entering PE with such a heavy vehicle is beyond my reasoning. I looked at some 03 and up 6.0L cals with my tuner and saw the 60 sec delay. I just need to get them to add it to the earlier years. They are great about doing that when I find these things.
