Fuel Strips (Film type fuel sensor)

[ilpo]

you're probably tired of doing it... but SOON you'll be able to do it with your GS-911 !!! 

Meaning calibration? I have switched mine without doing that and it worked out just fine.

[deilenberger]

ouch... didn't know you did it THAT many times Don!

you're probably tired of doing it... but SOON you'll be able to do it with your GS-911 !!! 

Luckily, I'm under the perpetual BMW fuel strip warranty. My first one failed at about 30 months, each one since then has lasted less than a year, and one was installed and was defective. So - BMW is picking up parts/labor forever..  The dealer now keeps one in stock for me.

[StephanT]

If anyone has any TB's (Technical Bulletins) concerning the Fuel Strip and Fuel strip calibration, pls let me know ;-)

[Shaggy]

I have an 09 GS, after 2 years had my fuel strip replaced under warranty, ive never really let the bike go down to less than 100 miles left well that was until a few months ago when i ran out of fuel with it reading 81 miles left! Really looking forward to being able to recalibrate

[StephanT]

if you're using a current Beta version, use the check for updates in the About screen.. otherwise use the GS-911downloader and get the newest Beta.. it has :

• Updated ESA calibration
• Fuel Strip calibration
• Windscreen motor calibration

best,
Stephan

[Shaggy]

  Fuel strip recalibrated it was reading 122 miles left, took out the strip left it overnight then connected it all up outside the tank,  ran the re-callibration prog, once it was all back together it showed the correct level and 45 miles left, excellent 

[sq5rk]

hi all
in my case didnt work. '09 gs, not adv. When tank is full, clock shows me around 700 or more km range. So like in adventure ? Removed strip, dried, and calibrated. Nothing has changed. Still strange reading. Any idea? Cheers from Poland - Romek

[StephanT]

maybe the strip is damaged... remember, the calibration is intended to calibrate a NEW fuel strip when it is installed.. (as part of the installation procedure) - naturally it cannot fix a broken strip

best,
Stephan

[sq5rk]

well, Im afraid you are right So its time to buy new one. Thanks for reply.

[Shaggy]

hi all
in my case didnt work. '09 gs, not adv. When tank is full, clock shows me around 700 or more km range. So like in adventure ? Removed strip, dried, and calibrated. Nothing has changed. Still strange reading. Any idea? Cheers from Poland - Romek

Did you take the bike for a ride? mine stayed at the same reading until i put it on the centre stand started it then ran it in second gear, it then rapidly changed reading to the correct amount

[sq5rk]

Did you take the bike for a ride?

Yes , I did. I thought the same. ~800 km's, but nothing has changed.

[Haakon]

How do the fuel level "strip" work?
My guess is (simply explained) its a plastic strip with a low heat element on one side and a series of heat sensitve resistors on the other side.
(the heat sensitive resistors can be PT100`s or some other type.)
(why PT resistors? PT`s is easily "printed" on plastic or whatever none conductive materials)
One drop of (conductive)moisture would result in a faulty reading.
----------------
The float type sensors also use resistance to meassure the fuel level.
The huge difference is its a basic "potentiometer" type device.
The more expensive ones are actully wirewound- meaning self cleaning.
The current used is also much higher = less sensitive to "slight contamination".
------------
I am sure the CANbus will not accept a disconnected fuelstrip as it monitors both the heating and resistor part.
To bypass the heating circuit must be easy- a plain resistor of the same value as the heating element.
How get a float sensor to work and show real values...- I do not know
Sorry to waste your time,
Haakon

     


 

   

[deciacco]

Stephan,

I was hoping you could explain the fuel strip values for me:

I've attached an image showing the reading form the gs911. The left shows the fuels strip idling while the right side shows the fuel strip being polled.

It looks like as long as the computer is turned ON there is a very minimal amount of current going to the heater. Usually, about 2.42mA. Can this vary from strip to strip? What is the "normal" value/range here? The strip heater voltage seems to be very minimal as well at 0.07V. The Fuel Sense Voltage is always 0 on my bike, I'm guessing this is for those equipped with a float, but have no idea. I don't understand the Film Sensor Heating percentage. When the fuel strip is being polled this seems to jump to 62.8%. Is this normal? Why wouldn't it hit 100%? Also when the strip is being read, the heater current jumps to 187.76mA and the voltage to 1.05V.

I'm trying to determine what these values are telling me and if they are withing the accepted ranges as I believe my fuel strip is on it's way out again.

Also, is it possible to show the resistance reading from the sensor circuit?

Thanks,

-E

[Haakon]

I know you asked for Stephans advice- I am NOT him!
I did reply to this thread earlier and pray THAT reply did not confuse you.
I have no real information on this topic and my reply was based on "industry" use of the same basic technology.
(not used any more- "abandoned" years ago)
--------------
I am again just "guessing":
I do not think the fuel level is constantly monitored. That would steal too much computer usage.
I guess its checked/ monitored maybe every second or MUCH less.
If the engine is not running maybe its NOT checked more than once- done when the ignition is turned on??
The bikes computer is "tiny"- engine managment is more important than fuel level- thus the fuel is checked more seldom.
BUT- I may be all wrong re this!!!- I am just guessing!!! 
 

[deciacco]

Haakon,

Thanks for your response. I have somewhat of an understanding of how it works at least based on this threadhttp://advrider.com/forums/showpost.php?p=18095884&postcount=48, I just don't understand the real-time values from the GS-911 as the strip is being polled.