E85 Sensor Info

[MN C5]

From the GMTech site

Flexible Fuel
Sensor
To measure the true ethanol alcohol percent-age and fuel temperature needed for proper engine operation, the L43 engine uses a flexi-ble fuel sensor. It's located on the top of the right side frame rail, behind the right front upper control arm. All fuel delivered to the engine passes through the flex fuel sensor forethanol measurement.Here's how the sensor determines alco-hol percentage and fuel temperature. Thesensor generates a digital signal that varies infrequency, based on ethanol percentage. By
measuring the frequency of the signal, thePCM can determine the ethanol percentage.A 50 Hz signal equals a zero percentage of ethanol. If a true E100 ethanol fuel (100 per-cent ethanol) was available, it would equal150 Hz. So an E85 fuel containing 85 percent ethanol should be about 135 Hz.The sensor controls the width of the digital signal (pulsewidth) to indicate fuel temperature. The sensor causes its output signal pulsewidth to be between 1 millisecond(equals a fuel temperature of -40 degrees
Celsius) to 5 milliseconds (equals a fuel temperature of 125 degrees Celsius).The flex fuel sensor has its own internal circuit diagnostic capabilities. If an internal sensor fault is detected, the output will be forced to 170 Hz if the fault is with the percentage-measuring circuits. Output will be forced to 0.5 millisecond pulsewidth and 170Hz if the fault is with the temperature-measuring circuits.

[TAQuickness]

cool. The way GM describes it, seems like a similar concept to blinker fluid

[GMPX]

I wonder how they 'actually' do it, I mean, what reacts with the ethanol to make a resistance or capacitance change that varies the frequency of the sensor. Sounds pretty neat to me.

Cheers,
Ross

[Tydriver]

I have a friend thats big into the MegaSquirt stuff.. We were talking about E85 the other day and he sent me this:

http://www.megamanual.com/flexfuel.htm

(Plz dont shoot me, I am 110% behind EFILive and the LSx PCMs, I am just trying to share some information.. More importantly, part #s and specs about how the sensor works.)

I tried searching for that sensor on eBay like it talks about in that link and also for the USER ID, but I think he probably got over run with requests and must have changed his ID. I couldnt find anything that seemed to match..
Once the LS6 is in place and running on unleaded in my Typhoon, I want to switch it over to E85. U can get it at the pump here. Its benefits are too damn appealing for a forced induction motor to overlook !


DOES ANYONE HAVE A CHEAPER SOURCE FOR THE SENSOR than $330+shipping from GMPartsdirect.com ??

[emarkay]

You can't run E85 unless all the fuel system components have been engineered for Ethanol! It's much more corrosive than gas, and needs to have special seals, lines and gaskets as well as filters in place.

Here's the list of pre-made vehicles that can use E85:

2006
3.5L Chevy Impala (LS, 1LT & 2LT)
3.5L Chevy Monte Carlo (LS and LT models only)

2005 - 2006
5.3L Vortec-engine Avalanche
5.3L Vortec-engine Police Package Tahoe*

2003 - 2006
5.3L V-8 engine Chevy Silverado and GMC Sierra half-ton pickups 2WD & 4WD
5.3L Vortec-engine Suburban, Tahoe, Yukon and Yukon XLs

2002
5.3L V-8 engine Chevy Silverado and GMC Sierra half-ton pickups 2WD & 4WD
5.3L Vortec-engine Suburban, Tahoe, Yukon and Yukon XLs
2.2L Chevrolet S-10 pickup 2WD
2.2L Sonoma GMC pickup 2WD

2000 - 2001
2.2L Chevrolet S-10 pickup 2WD
2.2L Sonoma GMC pickup 2WD

Source:
http://www.e85fuel.com/information/general_motors.php

[Tydriver]

You can't run E85 unless all the fuel system components have been engineered for Ethanol! It's much more corrosive than gas, and needs to have special seals, lines and gaskets as well as filters in place.

LOL, I always love it when people tell me I CANT do something.. I have been researching ethanol well before the gas crunch craze happened. I grew up in the plains states where ethanol is very big.. The tech school I went to even did testing with the FAA on utilization in piston engine aircraft ultimately obtaining STCs for 3 models. I'm well aware of the demands it places on the fuel system. I also have a friend thats currently running E85 in his Syclone (Circa 1991 fuel system) with no issues, he's only running a 50% mixture be mind you, this is on an OLDER ECM setup (thats fully tune-able also) and the stock fuel system.

I plan on installing all ethanol friendly fuel system components in the Typhoon as I build the fuel system anyhow so its not a big concern.. I want to run 100% E85 and maximize the benefits of the cleaner burning 105 octane fuel can offer.

Running 100% E85 on a non compatible vehicle can be an issue, I wouldnt do it in my beater, but plans are at this point to design the fuel system to handle it and I will be fine.