I do (hp tuners and a tech 2) and I’ll plug them in and find out. Not sure if a tech 2 will work with this rig.
Blackbear Performance Review
- Thread starter Bigburb3500
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That's pretty conclusive that it's not a FF system.
So here's what I found with HP Tuners, using their scanner app. Alcohol content was not a default channel for the app's home screen, but I was able to add it and then scan the ECU to see if there was any data available there. Sure enough, there is. Now I don't know if it's a calculated value based on O2 sensor data, or an actual hardware sensor value, but at least the ECU is capturing alcohol content data as a percentage. And the value seems plausible. Note, the ignition was on but the engine wasn't running for the screenshot below.
I can't imagine that there is a physical sensor on it, so I would bet it's a calculated percentage. They dropped the physical sensor from the GMT800s around 2005 or so.
Thanks, Steve. I think you’re right about not having a physical sensor, but I guess the question is still open as to whether or not it’s actually a stealth flex fuel truck.
Curiously, gmauthority says it's FF:
I would be inclined to do a little test with some E85 -- know your fuel trims with E10 first, then maybe mix 1/3 E85 (probably E50 or E70 at the pump) with 2/3 gas and see 1) if the STFTs go way positive, or settle down to a good value and 2) see what HP Tuners reads for alcohol content. And not a full fillup, just less than 1/2 a tank if it becomes an issue.
EDIT: I take that back, didn't read the fine print. Article says FF in the Savanna and Express only.
I would be inclined to do a little test with some E85 -- know your fuel trims with E10 first, then maybe mix 1/3 E85 (probably E50 or E70 at the pump) with 2/3 gas and see 1) if the STFTs go way positive, or settle down to a good value and 2) see what HP Tuners reads for alcohol content. And not a full fillup, just less than 1/2 a tank if it becomes an issue.
EDIT: I take that back, didn't read the fine print. Article says FF in the Savanna and Express only.
mikeyss
Full Access Member
It's odd that this article says the L96 has cathedral port heads, but those came with the 823 rec port heads.Curiously, gmauthority says it's FF:
I would be inclined to do a little test with some E85 -- know your fuel trims with E10 first, then maybe mix 1/3 E85 (probably E50 or E70 at the pump) with 2/3 gas and see 1) if the STFTs go way positive, or settle down to a good value and 2) see what HP Tuners reads for alcohol content. And not a full fillup, just less than 1/2 a tank if it becomes an issue.
EDIT: I take that back, didn't read the fine print. Article says FF in the Savanna and Express only.
Bigburb3500
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What is the physical difference between a FF and non-FF engine? Maybe a dumb question but I’m wondering if the “stealth” feature is there but the difference could be injectors or something else buried deep into the truck.
Maybe?
Maybe?
As I understand it from a GMT800 perspective, larger fuel injectors, a fuel pump that can pump more volume, and an E85 fuel table in the ECM. I'd be curious what others think the differences could be.
mountie
Supporting Member
I gotta do the Blackbear ( I keep considering it)......
Making a right turn from a light ( get ahead of oncoming traffic driving over the speed limit).....
( Screw them... they're speeding )... I have good acceleration, but the '05 Yukon is confused, with "how much throttle / gear it should be in".
It's like the ECM doesn't think fast enough......
Making a right turn from a light ( get ahead of oncoming traffic driving over the speed limit).....
( Screw them... they're speeding )... I have good acceleration, but the '05 Yukon is confused, with "how much throttle / gear it should be in".
It's like the ECM doesn't think fast enough......
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