Adjusting Syncro Fuel Sender (After the fact)

[livethevanlife]

Hey All. A number of years ago when I got my first Syncro one of the first things I needed to do was replace the fuel level sender in the tank. I did this before I learned that all of the aftermarket senders are not calibrated. So I replaced it and tossed the old one, and of course my gauge has never been accurate since. Does anyone have any tips on how to remove it and calibrate it without the old one as a reference? Right now with the tank full it reads half on the gauge.
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The Westy Bravo https://smallcar.com/westy-bravo/
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1991 Syncro Triple Knob Westfalia "Miki" 2.2l WBX
1992 Syncro Triple Knob Tintop "Schnitzel" 1.9AAZ
1990 Syncro Doka Subi 2.2l
1974 Thing
1989 Carat Tintop

[MarkWard]

The aftermarket sender I received was shipped by error. The vendor sold both at the time. The problem with the aftermarket sender was it did not sweep square to the bottom of the tank.

You will need to remove the sender to operate the arm and adjust the stops. With the sender removed and plugged in have someone watch the gauge while you work the sender arm.

If it is reading full at half a tank, You'd probably have to bend the arm up so the float doesn't top out as soon. Unfortunately to see the movement, you need at minimum the filler neck removed. What's more critical than reading full is that the reserve part of the gauge is accurate.

If you prefer to get scientific, here is a thread for testing the accuracy of the gauge without the sender. https://www.thesamba.com/vw/forum/viewtopic.php?t=465972

I have used these values and they are accurate.

[4Gears4Tires]

FWIW, when I swapped in my EJ25 I thought if I bent the arm "a little bit" I thought I could get it to read accurately. I used the OE as a template to try to bend it into place. Yeah.... It barely changed where my full mark is. The resistance must be different for the same sweep of the arm. Whole thing is dumb because my OE was working just fine. If I drop the tank again, I'm not messing with the replacement, I'm just putting the OE back in.
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'87 Syncro Ferric Oxyhydroxide Superleggera Edition
'85 Westy Sciuridae Domus Edition

[MarkWard]

You could technically compare the resistance of the sender against the R values in the thread I linked above. Unfortunately resistance goes up as the level goes down, so you can't really "trick" the sender by adding resistance externally.

[ALIKA T3]

Hi Shane!

I documented this sh!t on my IG stories last time I did it.

The arm is so off, i's unbelievable, not even close.

I can send you some screenshots, I know I sent them to a few mechanics out there

I don't have time to write a nice post , but you do need an old unit to compare the float position....
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http://www.thesamba.com/vw/forum/viewtopic.php?t=416343
Syncro http://www.thesamba.com/vw/forum/viewtopic.php?t=4...num+gadget

[livethevanlife]

Thanks Alika, you da man!
_________________
Vanagon Restorations www.LiveTheVanLife.com
The Westy Bravo https://smallcar.com/westy-bravo/
Vanagon Rentals https://www.PeaceVans.com/baja
1991 Syncro Triple Knob Westfalia "Miki" 2.2l WBX
1992 Syncro Triple Knob Tintop "Schnitzel" 1.9AAZ
1990 Syncro Doka Subi 2.2l
1974 Thing
1989 Carat Tintop

[bsrad]

[livethevanlife]

Alika sent them to me. I dont mind posting them here for him if he doesnt mind.
_________________
Vanagon Restorations www.LiveTheVanLife.com
The Westy Bravo https://smallcar.com/westy-bravo/
Vanagon Rentals https://www.PeaceVans.com/baja
1991 Syncro Triple Knob Westfalia "Miki" 2.2l WBX
1992 Syncro Triple Knob Tintop "Schnitzel" 1.9AAZ
1990 Syncro Doka Subi 2.2l
1974 Thing
1989 Carat Tintop

[ALIKA T3]

[tencentlife]

Even after you take the sender out and bend the arm to get a wider resistance range, you might still want to use a resistance translator to make the gauge read in a useful way:

https://www.tanksinc.com/index.cfm/page/ptype=prod...prd748.htm

Same item at Summit:
https://www.summitracing.com/parts/tnk-tan-mm

Easy to use, I can recommend it.

It's nice to have a decade box, too, so you don't need to have your actual fuel level at empty, full, or in between to do the calibrations. Get the tank near empty, go to the filling station with your ohmmeter, unplug the sender and record the ohms at near empty, then at two intermediate volumes, then at full. When you get home use the decade box to feed those resistance values into the translator and set up your gauge.

Decade boxes are common and cheap at Jeff's Place or any electronics supplier.
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Please don't PM here, I will not reply.

Experience is death to doctrine.

[MarkWard]

[bsrad]

What?! Metermatch!! Where has this been all my life? Ordered!

Thanks for sharing tencent..
_________________
Bill

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1987 Syncro Westy
1967 OG Single Cab
1976 FJ40

[ALIKA T3]

[MarkWard]

[ALIKA T3]

[zerotofifty]

Having owned a Bug as my first car, a car that never had a gas gage. I have gotten used to using my odometer as my gage. I guess I am old and set in my ways. Of course with the Bug I can remove the gas cap and see the gas level. Oh the simplicity of life of days gone by.