bmwe21.net forums

http://www.e21build.com/2013/11/p-is-for-progress.html

http://www.e21build.com/2013/11/seat-rails.html

Can anyone tell me what the resistance for the E21 tank sensor is at full/empty?

My google-fu only found this (http://forums.bimmerforums.com/forum/ar ... 92201.html) which states 74ohm empty and 3ohm full.

My fuel cell purportedly (I say this because the -AN fittings were different to what the sale stated!) came with a 90ohm "GM" spec sender - i.e. 90ohm when empty and 0ohm when full.

If all E21's do indeed expect 74ohm as "empty" then I will adjust this sender with a ~400ohm resistor in parallel with the sender (for a total resistance of 73.5ohm or as I like to call it "close enough")

Also, I assume the fuel guage is sent +12v and the other lead flies out to the fuel sender which is then grounded on the other side. Is this correct? If nobody answers that part I'll just assume so

http://www.e21build.com/2013/11/more-se ... ssion.html

http://www.e21build.com/2013/11/fuel-ga ... again.html

Can't you just switch 2 wires connected to the gauge?

Or am I talkng nonsenses?

I wish it were that easy.

Unfortunately since it's only resistance (which isn't polarity conscious) it won't make any difference which way the leads are connected to either the sender or the gauge; sometimes in this instance if the sender is mounted in the side of the tank you can rotate it 180 degrees so the float operates in the opposite direction but unfortunately as it's in the top of the tank it isn't that simple either.

Op-amp or transistor, or swap the sender (I don't think I can with this fuel cell) or gauge (it's not that pressing since it'll only really be me driving the car). An Op-Amp seems like a good option because I can use that to trigger a low fuel indicator light.

http://www.e21build.com/2013/11/wiper-p ... orted.html

http://www.e21build.com/2013/12/fan-and ... pport.html

http://www.e21build.com/2013/12/clearing-workspace.html

http://www.e21build.com/2014/02/bottom- ... there.html

http://www.e21build.com/2014/02/watercooled.html

http://www.e21build.com/2014/02/multipl ... heels.html

http://www.e21build.com/2014/03/extractors.html

Short drive video with the extractors.

Not game to give it too much throttle because of the driveshaft being out of balance and diff not welded yet; don't want either grenading. It gives you a bit of an idea anyway.