http://www.e21build.com/2013/11/p-is-for-progress.html
4.0L E21 Build
Re: My 3yr+ E21 Build
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
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
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Mihajlo
- E21 Pro
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- Joined: Thu Aug 23, 2007 11:07 am
- My E21(s): 1982 315swap323i
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Re: My 3yr+ E21 Build
Can't you just switch 2 wires connected to the gauge?
Or am I talkng nonsenses?
Or am I talkng nonsenses?
Understeer is when you hit the wall with the front of the car. Oversteer is when you hit the wall with the rear of the car.
Horsepower is how fast you hit the wall. Torque is how far you take the wall with you.
Horsepower is how fast you hit the wall. Torque is how far you take the wall with you.
Re: My 3yr+ E21 Build
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.
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.
Re: My 3yr+ E21 Build
Last edited by SileNceR on Thu Dec 12, 2013 4:27 pm, edited 1 time in total.
Re: My 3yr+ E21 Build
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.