Alcohol Level
Moderator
Joined: 01-23-2009
Posts: 26,532
From: Fredericksburg,VA
A few points:
on my car anyway, closed loop is attained within 2 minutes (usually much less).
So, if I have never used E85 at all, my ECM should be cool?
I have found wide variation of reported % using OBDII readers. Most of the time the pumps around here have a label that says "Contains 10% Ethanol", but usually the OBDII reports 0% sometimes up to 10%.
Where I can actually tell what is going on is the PID that measures the cat efficiency. When the level is at 10% the PID value is supposed to be above .05, when below 10% it's supposed to be above .035. I may have got those bassackward.
I generally fill up with more than 13 gallons, usually 2-4 times a week.
And the ethanol is added to the delivery truck at the tank farm by the driver; if you know any truck drivers you know why I'm skeptical.
on my car anyway, closed loop is attained within 2 minutes (usually much less).
So, if I have never used E85 at all, my ECM should be cool?
I have found wide variation of reported % using OBDII readers. Most of the time the pumps around here have a label that says "Contains 10% Ethanol", but usually the OBDII reports 0% sometimes up to 10%.
Where I can actually tell what is going on is the PID that measures the cat efficiency. When the level is at 10% the PID value is supposed to be above .05, when below 10% it's supposed to be above .035. I may have got those bassackward.
I generally fill up with more than 13 gallons, usually 2-4 times a week.
And the ethanol is added to the delivery truck at the tank farm by the driver; if you know any truck drivers you know why I'm skeptical.
Senior Member
Joined: 04-26-2009
Posts: 669
From: City of Champions
The 2009 HHR was the 1st 4 banger, for GM, to to be flex fuel capable…
Starting in 2012, GM went back to using a sensor, to calculate Ethanol percentage...
Last edited by 2005HHRauto; Mar 8, 2015 at 03:45 PM.
Senior Member
Joined: 04-26-2009
Posts: 669
From: City of Champions
A few points:
on my car anyway, closed loop is attained within 2 minutes (usually much less).
So, if I have never used E85 at all, my ECM should be cool?
I have found wide variation of reported % using OBDII readers. Most of the time the pumps around here have a label that says "Contains 10% Ethanol", but usually the OBDII reports 0% sometimes up to 10%.
Where I can actually tell what is going on is the PID that measures the cat efficiency. When the level is at 10% the PID value is supposed to be above .05, when below 10% it's supposed to be above .035. I may have got those bassackward.
I generally fill up with more than 13 gallons, usually 2-4 times a week.
And the ethanol is added to the delivery truck at the tank farm by the driver; if you know any truck drivers you know why I'm skeptical.
on my car anyway, closed loop is attained within 2 minutes (usually much less).
So, if I have never used E85 at all, my ECM should be cool?
I have found wide variation of reported % using OBDII readers. Most of the time the pumps around here have a label that says "Contains 10% Ethanol", but usually the OBDII reports 0% sometimes up to 10%.
Where I can actually tell what is going on is the PID that measures the cat efficiency. When the level is at 10% the PID value is supposed to be above .05, when below 10% it's supposed to be above .035. I may have got those bassackward.
I generally fill up with more than 13 gallons, usually 2-4 times a week.
And the ethanol is added to the delivery truck at the tank farm by the driver; if you know any truck drivers you know why I'm skeptical.
Last edited by 2005HHRauto; Mar 8, 2015 at 03:41 PM.
Joined: 09-23-2005
Posts: 4
From: Michigan
2005HHRauto I'm making an assumption here based on your explanation that GM is/was using narrow band O2 sensors on those cars. By monitoring the O2 swing and the STFT & LTFT's over time the ECM would determine what level of Ethanol was in the fuel load. Am I correct?
Moderator
Joined: 01-23-2009
Posts: 26,532
From: Fredericksburg,VA
Sort of (it's a computer thing). But the SS has a wide band #1 sensor.
Senior Member
Joined: 09-07-2008
Posts: 1,016
From: Mebane, NC
Roger that, I'm a code writer as well, adaptive learning, among other things is what we call it. The problem with that as 2005HHRauto indicated you have to let something run long enough to develop the trend. If you do the short hop thing the long term results aren't going to be good.
Senior Member
Joined: 06-20-2011
Posts: 737
From: Savanna Illinois
Evidently not the '06. My daughter was using the HHR for a while, while I was working on her Neon. She found gas for a much lower price and put it in. It turned out that the gas was the E85 so mostly alcohol.
She asked me what was wrong with the car because she was getting really bad mileage. One tank was lasting about 2/3rds as long as a tank of the regular 10% gas.
I checked a lot of things out and could not find anything particularly 'wrong' with the car. After talking a bit I discovered she had put the 'cheaper' gas in.
The car ran alright but was a bit doggy when you would try to pass someone. Once she started getting the regular 10% gas everything went back to normal. I figure having the higher amount of alcohol probably just dried and cleaned the fuel system out.
Everything is back to normal and has been for a year or so. The kid learned that paying less for gas isn't always a good thing.
She asked me what was wrong with the car because she was getting really bad mileage. One tank was lasting about 2/3rds as long as a tank of the regular 10% gas.
I checked a lot of things out and could not find anything particularly 'wrong' with the car. After talking a bit I discovered she had put the 'cheaper' gas in.
The car ran alright but was a bit doggy when you would try to pass someone. Once she started getting the regular 10% gas everything went back to normal. I figure having the higher amount of alcohol probably just dried and cleaned the fuel system out.
Everything is back to normal and has been for a year or so. The kid learned that paying less for gas isn't always a good thing.
Moderator
Joined: 01-23-2009
Posts: 26,532
From: Fredericksburg,VA
Evidently not the '06. My daughter was using the HHR for a while, while I was working on her Neon. She found gas for a much lower price and put it in. It turned out that the gas was the E85 so mostly alcohol.
She asked me what was wrong with the car because she was getting really bad mileage. One tank was lasting about 2/3rds as long as a tank of the regular 10% gas.
I checked a lot of things out and could not find anything particularly 'wrong' with the car. After talking a bit I discovered she had put the 'cheaper' gas in.
The car ran alright but was a bit doggy when you would try to pass someone. Once she started getting the regular 10% gas everything went back to normal. I figure having the higher amount of alcohol probably just dried and cleaned the fuel system out.
Everything is back to normal and has been for a year or so. The kid learned that paying less for gas isn't always a good thing.
She asked me what was wrong with the car because she was getting really bad mileage. One tank was lasting about 2/3rds as long as a tank of the regular 10% gas.
I checked a lot of things out and could not find anything particularly 'wrong' with the car. After talking a bit I discovered she had put the 'cheaper' gas in.
The car ran alright but was a bit doggy when you would try to pass someone. Once she started getting the regular 10% gas everything went back to normal. I figure having the higher amount of alcohol probably just dried and cleaned the fuel system out.
Everything is back to normal and has been for a year or so. The kid learned that paying less for gas isn't always a good thing.
Moderator
Joined: 01-23-2009
Posts: 26,532
From: Fredericksburg,VA
New question.
I refilled yesterday with 12.6 gallons. This morning the alcohol was measured at 4.6%. After driving 150 miles the alcohol is showing 0.8%.
The reason I'm monitoring is I'm still fighting P0420 and the target number changes with alcohol percentage. (Oxygenated fuel reads differently to O2sensors).
I had the same results with a different ECU, 3 different cats and 6 different sensors. No exhaust leaks. No vac leaks. New injectors fixed it for 2 months.
I refilled yesterday with 12.6 gallons. This morning the alcohol was measured at 4.6%. After driving 150 miles the alcohol is showing 0.8%.
The reason I'm monitoring is I'm still fighting P0420 and the target number changes with alcohol percentage. (Oxygenated fuel reads differently to O2sensors).
I had the same results with a different ECU, 3 different cats and 6 different sensors. No exhaust leaks. No vac leaks. New injectors fixed it for 2 months.