pwtr02ss
Full Access Member
Well, brother. I know it's not coming from a she, but it's perfect :hug:I wish that was what she said.
Growing up doesn't have to suck
- Thread starter iamdub
- Start date
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iamdub
Full Access Member
Latest sample. I'm calling it 69%
But it's calculating it as 56%
I got nine gallons of E85 and saw that Fuel Composition Learn went to "Active" right after leaving the gas station. Maybe 2-3 miles later, it was back to 56% and "Inactive"
I'll see what this current tank percentage is then probably switch back to E10 93.
But it's calculating it as 56%
I got nine gallons of E85 and saw that Fuel Composition Learn went to "Active" right after leaving the gas station. Maybe 2-3 miles later, it was back to 56% and "Inactive"
I'll see what this current tank percentage is then probably switch back to E10 93.
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iamdub
Full Access Member
On the way to get that fuel, I hit a dip that's in a curve coming off the interstate and immediately got all the suspension warnings (Traction control Off, StabiliTrak Off, Service Suspension System, ABS light on, etc.). This has happened before under these exact same circumstances. It goes away after some driving and key on/off cycles. Wouldn't go away after this one so I checked for codes:
I pulled off into a cane field, laid out a towel and checked the connector on the top of the frame rail and traced the wire to the sensor on the axle tube. Found nothing apparent. Got back on the road while monitoring and saw this:
So, either a dead sensor or fault in the circuit. It happened when hitting that dip, so I'm now wondering if I have an axle moving just enough to contact the sensor. Surely my bearings aren't that bad. I'll try to find time to check it out soon.
I pulled off into a cane field, laid out a towel and checked the connector on the top of the frame rail and traced the wire to the sensor on the axle tube. Found nothing apparent. Got back on the road while monitoring and saw this:
So, either a dead sensor or fault in the circuit. It happened when hitting that dip, so I'm now wondering if I have an axle moving just enough to contact the sensor. Surely my bearings aren't that bad. I'll try to find time to check it out soon.
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iamdub
Full Access Member
I had just hit an odometer milestone as I was pulling off into that cane field, so I took some pics:
This was at 9PM, so full moon with long exposure:
This was at 9PM, so full moon with long exposure:
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Don’t you have the actual sensor in your rig..? Rather than the “calculator” typical with the GMT900? That’s annoying af that it’s not getting the correct percentage.Latest sample. I'm calling it 69%
View attachment 396320
But it's calculating it as 56%
View attachment 396321
I got nine gallons of E85 and saw that Fuel Composition Learn went to "Active" right after leaving the gas station. Maybe 2-3 miles later, it was back to 56% and "Inactive"
I'll see what this current tank percentage is then probably switch back to E10 93.
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iamdub
Full Access Member
The police Explorer? I feel I'm missing something.
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iamdub
Full Access Member
I don't because I haven't retrofitted (yet?). I was gonna do it then found that the "virtual sensor" was reporting MUCH more accurately, within 2% of actual, since replacing the O2 sensors. Now it's back to being way off. Not as bad as before when it was stuck around 22%. But still far enough off to be disadvantageous. Also, the really short learning cycle is an annoying mystery.
randeez
Full Access Member
should be able to adjust learning cycle in the tune...
since youre a big tuner guy now
swathdiver
Full Access Member
It's not done, it'll keep analyzing the alcohol content for a few more days.
If you did not use GM OE sensors that could be why the readings are off. Denso and Bosch are not OE as I've been learning these past few weeks. All those who are using them are not getting accurate numbers.
I'm sorry I meant 20 second mark.
George B
¯\_(ツ)_/¯
Please elaborate on the sensor comment.
swathdiver
Full Access Member
The GM sensors are calibrated to work with the ECM. The Denso and Bosch sensors don't look like the OE sensors and as I've been learning on this and other forums, doesn't calculate the alcohol content properly. Or rather, the information they provide to the ECM doesn't allow it to calculate it properly.
In most cases when the alcohol content got out of whack, it was either old OE or aftermarket sensors. Guys are putting in Denso and Bosch sensors and still having problems with the alcohol percentages creeping up and causing them problems.
George B
¯\_(ツ)_/¯
Not saying it’s not true but we have had much discussion on this and most agreed the Denso sensors were fine and in fact may be the manufacturer of the OEM units anyway. I took denso units out of mine at 70k and replaced them with denso units.
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iamdub
Full Access Member
Damned straight. I'm all over them tire circumference tables. Might be doing that tomorrow, actually.
I'll look into that learning cycle stuff. Can I adjust it "backwards", like change it to understand whatever it's currently reading as 56% as the 69% that I physically measured and have it shift the scale accordingly?
swathdiver
Full Access Member
Well, I compared them side by side (pictures on Rock Auto) and they look very different. Then there was a rash of guys with alcohol content problems over the course of a few days on this forum, GM-Trucks and Silverado/Sierra and the common denominator was the aftermarket O2 sensors. Once they changed them to GM OE, the problem went away. Coincidence?
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iamdub
Full Access Member
Well, that's a ray of hope. I saw that it remained in alcohol content learning mode for around 7-8 miles last time I was monitoring and it settled fairly accurately. This time it was learning for only 2, maybe 3 then stopped and with the content at 56%, just as it was before. I drove about 80 miles today but wasn't monitoring. I wanna spend some time tomorrow troubleshooting that speed sensor issue. If I can manage that, I'll pull another fuel sample.
Do you know if the PCM responds quicker and learns sooner with the physical sensor?
I used Denso 234-4668 (which I now see also shows up as "Denso 12594452"
). I thought Denso provided sensors for AC Delco and, therefore, were OEM. Would the physical sensor remove the O2 sensors from the equation for calculating alcohol content?
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iamdub
Full Access Member
First off, I have little faith in online retailer photos.
But, ya know something... They have counterfeit NGK and AC Delco spark plugs (among others). I wonder if I and others have gotten counterfeit/inaccurate Denso O2 sensors. So, even if Denso made them for ACD and the legitimate ones in the Denso boxes were all equal and fine, we still would have who-knows-what brand sensors and the resulting issues.
George B
¯\_(ツ)_/¯
It probably isn’t a coincidence and the sensors I took out were different in appearance from the ones I put in. I chalked it up to a design change or something. I just raised the point that many of us are running the denso sensors. Had I even had a suspicion they wouldn’t be as good as originals I would have spent the $$. We were all under the impression they were good.
