Ethanol percentage flex fuel

[wsteele]

The 2007s don't have the same menu and it is not in the engine section either for some reason.

I think I went through every page of every module (not just engine/powertrain) and can't find any fuel pressures reference. I have trims, but those are expressed in percentages and I assume reflect adjustment to the PW's, versus anything related to pressures.

I will have to find my fuel pressure gauge. I did a conversion from carb to EFI on an old car I had long ago, using a Megasquirt ECU, my own fabricated intakes, rails and TB's (basically old downdraft Weber carbs), etc. During that time I collected about every single item one might need to build an EFI system, so I am pretty sure I have a gauge somewhere.

 

[Fless]

I think I went through every page of every module (not just engine/powertrain) and can't find any fuel pressures reference. I have trims, but those are expressed in percentages and I assume reflect adjustment to the PW's, versus anything related to pressures.

I will have to find my fuel pressure gauge. I did a conversion from carb to EFI on an old car I had long ago, using a Megasquirt ECU, my own fabricated intakes, rails and TB's (basically old downdraft Weber carbs), etc. During that time I collected about every single item one might need to build an EFI system, so I am pretty sure I have a gauge somewhere.

You can always "rent" one from your auto parts store for a day or two.

 

[kbuskill]

Well I, for one, am convinced. I think this also explains the intermittent extended crank that I sometimes experience.

I went ahead and ordered the fuel pump assembly from RA.

I went with the Delphi, as opposed to the "Genuine GM" because the Delphi comes with a Lifetime warranty as opposed to the Genuine GM's 24 month warranty.

I made sure to order the Flex fuel pump.

I guess time will tell if this was the right move.

Now to convince my son to put it in...

 

[gooffeyguy]

I think I went through every page of every module (not just engine/powertrain) and can't find any fuel pressures reference. I have trims, but those are expressed in percentages and I assume reflect adjustment to the PW's, versus anything related to pressures.

I will have to find my fuel pressure gauge. I did a conversion from carb to EFI on an old car I had long ago, using a Megasquirt ECU, my own fabricated intakes, rails and TB's (basically old downdraft Weber carbs), etc. During that time I collected about every single item one might need to build an EFI system, so I am pretty sure I have a gauge somewhere.

Does your bluetooth dongle app show fuel pressure, or can you create custom pids?

Sent from my SM-G930V using Tapatalk

 

[kbuskill]

Accidental post, can't delete.

 

[wsteele]

Does your bluetooth dongle app show fuel pressure, or can you create custom pids?

Sent from my SM-G930V using Tapatalk

No, as I posted after I got the initial results, neither the Tech 2 or the dongle displays the fuel pressure. I am assuming my model year doesn't provide that information or the Tech 2 would display it.

 

[wsteele]

So here is the clip of the Tech 2's fuel trim data. Sorry, I realized I was scrolling pretty fast, should have done a page at a time and hovered on each page longer.

 

[wsteele]

Another thing I thought of (if the fuel pressures looked OK) is I may restore my stock tune from my Diablo Predator. Just do it before I refill the tank and then drive around with AFM on for two days until I am sure the Ethanol relearn is done. I have a pretty good baseline in the E10 gas I am using, so if it recalcs the Ethanol even close to what I pump into it, I will know it is the Diablo tune that is causing the foulup.

I have to say, it was around when I turned off the AFM with the Diablo Predator that I noticed the very rich warm ups. Might be a coincidence, but might not as well.

 

[kbuskill]

Another thing I thought of (if the fuel pressures looked OK) is I may restore my stock tune from my Diablo Predator. Just do it before I refill the tank and then drive around with AFM on for two days until I am sure the Ethanol relearn is done. I have a pretty good baseline in the E10 gas I am using, so if it recalcs the Ethanol even close to what I pump into it, I will know it is the Diablo tune that is causing the foulup.

I have to say, it was around when I turned off the AFM with the Diablo Predator that I noticed the very rich warm ups. Might be a coincidence, but might not as well.

Keep in mind that when you swap tunes it takes 100-150 miles for the fuel trims to level out, that is why Lew tells you to drive the truck that distance before logging again.

 

[wsteele]

Keep in mind that when you swap tunes it takes 100-150 miles for the fuel trims to level out, that is why Lew tells you to drive the truck that distance before logging again.

I hate the idea of turning my AFM back on after it being off. I really hate the idea of turning it on for 150 miles...

Maybe it will be the fuel pressure.

 

[George B]

I hate the idea of turning my AFM back on after it being off. I really hate the idea of turning it on for 150 miles...

Maybe it will be the fuel pressure.

You can always buy a Range disabler and then sell it here on the forum...

 

[kbuskill]

I hate the idea of turning my AFM back on after it being off. I really hate the idea of turning it on for 150 miles...

Maybe it will be the fuel pressure.

You can always buy a Range disabler and then sell it here on the forum...

Or you could wait until my fuel pump gets swapped and see if it clears up my issue and then you will know.

On another note, thinking about the new fuel pump...

Do you think I should use the Tech2 to reset the fuel pump trim and/or the LTFT/STFT/E% after the new pump goes in or should I just wait and see if everything recalibrates itself???

@swathdiver is there anything you have seen in the service manual that tells you what the proper procedure is after a new pump is installed?

I can go pilfer through the service manual myself, I just thought maybe you might know off the top of your head.

 

[wsteele]

You can always buy a Range disabler and then sell it here on the forum...

Been there, done that.

 

[George B]

Or you could wait until my fuel pump gets swapped and see if it clears up my issue and then you will know.

On another note, thinking about the new fuel pump...

Do you think I should use the Tech2 to reset the fuel pump trim and/or the LTFT/STFT/E% after the new pump goes in or should I just wait and see if everything recalibrates itself???

@swathdiver is there anything you have seen in the service manual that tells you what the proper procedure is after a new pump is installed?

I can go pilfer through the service manual myself, I just thought maybe you might know off the top of your head.

I wouldn't change too many things at once.

 

[wsteele]

Or you could wait until my fuel pump gets swapped and see if it clears up my issue and then you will know.

On another note, thinking about the new fuel pump...

Do you think I should use the Tech2 to reset the fuel pump trim and/or the LTFT/STFT/E% after the new pump goes in or should I just wait and see if everything recalibrates itself???

@swathdiver is there anything you have seen in the service manual that tells you what the proper procedure is after a new pump is installed?

I can go pilfer through the service manual myself, I just thought maybe you might know off the top of your head.

Actually, I was just wondering if I had to worry about fuel trims and calcs resetting, given I only used the AFM Disable function. I didn't use their canned tunes.

 

[kbuskill]

I wouldn't change too many things at once.

This is what I am thinking too, I just wasn't sure what the service manual said as I haven't dug into it yet. I am certain there is a "proper procedure" for swapping the fuel pump.

 

[George B]

Actually, I was just wondering if I had to worry about fuel trims and calcs resetting, given I only used the AFM Disable function. I didn't use their canned tunes.

2007 = 4l60 so no M5 option right?

 

[kbuskill]

Actually, I was just wondering if I had to worry about fuel trims and calcs resetting, given I only used the AFM Disable function. I didn't use their canned tunes.

I thought you had a custom tune from Lew?

 

[wsteele]

2007 = 4l60 so no M5 option right?

Yes, no M5 option, just 4 gears.

 

[wsteele]

I thought you had a custom tune from Lew?

No, just used the Diablo Predator to turn off AFM. When I said restore the tune, I was just referring to the firmware image being restored with V4 mode enabled.