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WOT O2 Question

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Old Jul 1, 2009 | 10:20 PM
  #21  
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From what I see on the scan, the injector pulse width is the same, the LTFT on bank 2 is .08% at WOT were as it is 0 on bank 1. Not all that far apart. I do not think the PCM is the problem. Looks more like a missfire at WOT, which could be from a bad plug or injector. It also could be an exhaust leak pulling O2 into the exhaust and causing the sensor to read the way it is. If this is the case, it would be also pulling in o2 while driving under normal conditions. This will cause the LTFT to record this and try to correct for it, which might explain the minor difference in WOT LTFT from bank to bank. When you go into PE mode the PCM zero's the STFT but it will carry over a value from the LTFT in an attempt to correct WOT fueling do to current conditions. Do you have headers on the car? If so which O2 sensors are you using at this time?
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Old Jul 2, 2009 | 08:39 AM
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Originally Posted by Texas_WS6
From what I see on the scan, the injector pulse width is the same, the LTFT on bank 2 is .08% at WOT were as it is 0 on bank 1. Not all that far apart. I do not think the PCM is the problem. Looks more like a missfire at WOT, which could be from a bad plug or injector. It also could be an exhaust leak pulling O2 into the exhaust and causing the sensor to read the way it is. If this is the case, it would be also pulling in o2 while driving under normal conditions. This will cause the LTFT to record this and try to correct for it, which might explain the minor difference in WOT LTFT from bank to bank. When you go into PE mode the PCM zero's the STFT but it will carry over a value from the LTFT in an attempt to correct WOT fueling do to current conditions. Do you have headers on the car? If so which O2 sensors are you using at this time?
The car is bone stock. I haven't looked to see the the O2s have been replaced, but I'm betting they are original. The car did throw a P0410 code just recently. Even though its a check valve, I suppose its possible for it to fail open, which could cause an exhaust leak. I removed the AIR equipment last night. Going to flush the coolant tonight or tomorrow and then I will start driving it again.
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Old Jul 2, 2009 | 09:49 AM
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Is that the only code you have had? DO you hear pinging? Post up the tune for inspection please. It might have been changed before you got the car. I am assuming you are not the original owner. It very well could be a bad O2 sensor.
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Old Jul 3, 2009 | 06:04 PM
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4th owner. Posted tune. I changed some little things (fans, !AIR, !RGR, etc), but nothing related to fueling or spark. I briefly scanned it again. The fuel trims probably arent accurate. I flushed the coolant which required pulling the battery, so they reset. I also removed the AIR and EGR and blocked them off.

The problem is the same at WOT and its now noticeable at part throttle under load. I swapped the sensors and the problem stays on bank 1. Since its isolated to one bank, Im thinking its not fuel pressure. The plugs were changed recently, so I'm going to pull those. Maybe one is cracked or one of the wires is going bad.
Attached Files
File Type: hpt
Formy Basic.hpt (445.5 KB, 99 views)
File Type: hpl
formy3.hpl (129.5 KB, 79 views)
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Old Jul 4, 2009 | 08:23 AM
  #25  
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Is it smoking? While you have the plugs out go ahead and check the compression. I bet there is nothing wrong with the cylinders but check compression too so you know for a fact what you have. I am betting it will be a plug, maybe a plug wire got damaged, or injector, or injector wiring, and don't forget to look at the ignition wiring for the coils. I am going to look your tune over just for grins.
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Old Jul 4, 2009 | 10:55 AM
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No smoke. I pulled bank 1 plugs last night, found no issues. reinstalled and all the part throttle problems are gone. WOT issue remains
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Old Jul 4, 2009 | 05:54 PM
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Looking at your VE table, everything below 5200 rpm is leaner, between 8 and 11 points. The injector flow rate looks like it is low as well. What year f-body is this? The timing tables look like they have 10 degrees of timing added to them almost everywere. This will explain the knock retard. I also see that someone has plaid with your knock retard and knock settings. You can get on the tune repository and find a good stock tune to compare from. Looking at what all that has been changed, I bet you are in fact running lean at WOT. Get a good WB on the car, and redue your WOT tunning. Your VE table is very lean and I would think that is were you need to start working at. DO NOT DUE ANY WOT TUNING WITHOUT THE WB!!! Drop your timing down a little in the WOT zones and work on timing later after you get the fueling corrected. Also, have you posted this on HP Tuners BB? If not, you should. There are plenty of great tuners there that will help you. Good luck.
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Old Jul 4, 2009 | 06:17 PM
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I have no interest in tuning the fuel or spark on this car, stock will be sufficient.

That being said, the car is a 2000 model Formula M6. I found a stock file. You must have been looking at a bad example or another year, my tune is stock in the areas you mentioned.


I did post up on HPT tuning forum, but got a bunch of slapdicks that had nothing to offer. Thanks for all the help, info has been much better over here.
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Old Jul 4, 2009 | 06:21 PM
  #29  
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Originally Posted by Texas_WS6
Looking at your VE table, everything below 5200 rpm is leaner, between 8 and 11 points. The injector flow rate looks like it is low as well. What year f-body is this? The timing tables look like they have 10 degrees of timing added to them almost everywere. This will explain the knock retard. I also see that someone has plaid with your knock retard and knock settings. You can get on the tune repository and find a good stock tune to compare from. Looking at what all that has been changed, I bet you are in fact running lean at WOT. Get a good WB on the car, and redue your WOT tunning. Your VE table is very lean and I would think that is were you need to start working at. DO NOT DUE ANY WOT TUNING WITHOUT THE WB!!! Drop your timing down a little in the WOT zones and work on timing later after you get the fueling corrected. Also, have you posted this on HP Tuners BB? If not, you should. There are plenty of great tuners there that will help you. Good luck.

I'm not sure what file you are looking at, but except the changes he listed (and some TM/TC stuff), it's a stock 9381344 OS/cal. If you are comparing it to something, you may check what you are comparing it against.
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Old Jul 5, 2009 | 10:52 AM
  #30  
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I checked it against my stock 02 WS6 file from my car. I did not see what year his was. That being said, why is there such a large difference in timing and VE fueling from 2000 Formy to 02 WS6? Mine has more VE fueling but alot less timing. I will double check my stock tune to some off of the tune repository to make sure what I think is my original tune is in fact stock.

That said, I still think the car is running lean at WOT. But we will not know this without a WB on the car. I can tell you from my experience the two banks do not run exactly the same, close but not the same. I use two WB AFX NGK's on my car. One on each bank. I do not remember which one runs leaner but it runs about .2 AFR leaner then the other bank. It did this with my cam only 346 with headers and my new 408 with headers. I just re-installed my stock manifolds and cat cut outs with a new SLP "Y" pipe for my GT88 rear mount kit. If I get a chance I will light it up and check to see if it does the same thing with the stock manifolds before I get the turbo kit finished and post up if there is still a difference.
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Old Jul 5, 2009 | 10:59 AM
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The cam in the 01-02 cars cam is significantly different than earlier years; I suppose it's related to the removal of external EGR. In OEM form, the 01-02 don't want anywhere near as much timing as earlier years.
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Old Jul 5, 2009 | 01:34 PM
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i would look into the cause for the p0410 code, that may be the 'wot lean" issue, i googled the code , it states that there are two check valves in the system, one for each bank. if in fact you do have two check valves, and one stuck open , then, i could see the respective bank going lean, it would be like having an exhaust leak. doesnt the air system kick in only when the car is cold for improved emissions?
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Old Jul 5, 2009 | 02:32 PM
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sounds like a good place to start!
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Old Jul 5, 2009 | 08:52 PM
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I removed the AIR system completely and blocked it off hoping that would fix it and it didn't change anything.

Im not installing a wideband on a bonestock car to troubleshoot a problem. I realize that the wideband would tell me if it was lean, but that still doesn't tell me anything meaningful. Be realistic, if I came and said WB showed lean, you'd just tell me to check fuel pressure or injectors right?
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Old Jul 5, 2009 | 08:55 PM
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I see lots of bad MAFs, but the part throttle trimming doesn't necessarily support that; usually they are in the +20s. You have a buddy with a stock MAF that you could try out?
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Old Jul 5, 2009 | 09:20 PM
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Originally Posted by A-Dub
I removed the AIR system completely and blocked it off hoping that would fix it and it didn't change anything.

Im not installing a wideband on a bonestock car to troubleshoot a problem. I realize that the wideband would tell me if it was lean, but that still doesn't tell me anything meaningful. Be realistic, if I came and said WB showed lean, you'd just tell me to check fuel pressure or injectors right?
so swap injectors, it isn't that bad, is it? if the indication follows, your good to go. hell, why don't you just add some lucas injector cleaning solution. i rely and trust my narrow band indications as much as my wideband indcations, the narrowbands have been very consistant and predictable throughout all the data logging i have done. so i have to agree that a wideband is not necessary for t/s a stock tune.
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Old Jul 5, 2009 | 09:36 PM
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Originally Posted by A-Dub
I removed the AIR system completely and blocked it off hoping that would fix it and it didn't change anything.

Im not installing a wideband on a bonestock car to troubleshoot a problem. I realize that the wideband would tell me if it was lean, but that still doesn't tell me anything meaningful. Be realistic, if I came and said WB showed lean, you'd just tell me to check fuel pressure or injectors right?
No, bone stock, I would look at the CAT(s) being plugged up. Sounds like just the begining of massive weirdness.

Don't over-think the obvious.
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Old Jul 6, 2009 | 08:24 AM
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Originally Posted by Doc
Sounds like just the begining of massive weirdness.
.
No kidding!
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Old Jul 6, 2009 | 09:23 AM
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Originally Posted by A-Dub
I removed the AIR system completely and blocked it off hoping that would fix it and it didn't change anything.

Im not installing a wideband on a bonestock car to troubleshoot a problem. I realize that the wideband would tell me if it was lean, but that still doesn't tell me anything meaningful. Be realistic, if I came and said WB showed lean, you'd just tell me to check fuel pressure or injectors right?

Your right, it is stupid to trouble shoot with a WB. So why the heck do you have HP Tuners? Man that was a shitty statment you made. I am trying to help you. I trouble shoot with mine all the time. I am an industrial mechanic and I use my Ecom (Emissions equipment that messures O2, NOx, No2, Co, etc.) all the time to trouble shoot, and to tune! I must be an idiot for thinking you can use it to trouble shoot and then to tune WOT with, which you have to have to tune WOT. So forgive me for assuming you have HP Tuners so you must be or want to be serious about tuning your car.

I am done trying to help you. Watch out every one else who wants to help here.
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Old Jul 6, 2009 | 12:39 PM
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I agree with Jon and Texas. You need a wideband to troubleshoot A/F ratio tuning. Do not try to use your stock narrowband O2s to tune for WOT. You will blow up your motor!

Narrowbands are only capable of reading slightly above and below 14.7. (thus the term "narrow") So you want you see if your motor is lean, right? Well, a narrowband can't tell the difference between 14.4 and 12.8 so you might think you're A/F ratio is ok, but is isn't. Anybody that argues with this I will personally kick in the *****.

Get access to a wide band or don't mess with the VE table.

Dan
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