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Wed Jul 18, 2018 1:50 pm

Hello,

I have searched many threads on this but am still not quite sure of the answer. I have a 73 standard beetle. I installed a new fuel sending unit with float, added a separate ground and checked all the connections by the gauge and exciter. The gauge did not used to work but now it does. It only goes up to 1/2 tank.

Question-Is there a way to calibrate the gauge system without removing the gas from the tank?

Thanks for the advice,

Web

Wed Jul 18, 2018 2:30 pm

Measure the voltage at the input side of the fuel gauge vibrator, it should be very close to the voltage measured at the battery. If not, this will need to be corrected before attempting to adjust the sending unit.

Wed Jul 18, 2018 6:27 pm

http://www.midsouthvw.com/TechTips/tech_tip_FuelGauge.htm

Thu Jul 19, 2018 7:50 am

I installed a new sending unit. Before that the gauge would not do anything. Wouldn't a new sending unit be adjusted correctly, meaning the issue is the vibrator or gauge itself?

web

Thu Jul 19, 2018 8:05 am

I think it was ashman40 who has an awesome thread on sender calibration done by bending the float arm.

I tested my new sender out of the tank to get full range and then used his method measuring tank depth with a paint stick and bending the float arm accordingly. Mine is calibrated so as the needle reaches the "R" hash, I have very close to one gallon left in the tank.

Took a couple tank fulls to get it right as I was eyeballing the underside of the tank to gauge what a gallon volume would look like.

Thu Jul 19, 2018 8:17 am

I use a VDO Gauge Check device to check gauge operation when it is fully installed. This will give indication as to whether the gauge/wiring is at fault or the sender.

Thu Jul 19, 2018 10:24 am

cool thanks. How do I find the ashman40 thread?

Thu Jul 19, 2018 10:39 am

I can't find the one I mentioned, but these are golden.

ashman40:

https://www.thesamba.com/vw/forum/viewtopic.php?t=703048&highlight=fuel+gauge

vwJimbo:

https://www.thesamba.com/vw/forum/viewtopic.php?t=690022

Thu Jul 19, 2018 12:17 pm

If you know how much gas is in the tank, say 5 gal.s, bend the arm until the gage reads 1/2 tank. Fine tune from there so you have a reserve before you run out, by driving until almost empty (or empty if you like) and have a gal. can of gas with you and pore it in and set the gage to just above reserve.

Mon Jun 29, 2020 2:46 pm

Hi, I have the same issue, I have replaced the sender, vibrator and gauge unit and get the same issue seen here of 3/4 on the gauge when the tank is full.

I seen that you can adjust the gauge itself, will it adjust another 1/4 to full and will it alter the empty setting?

Mon Jun 29, 2020 3:05 pm

https://www.thesamba.com/vw/forum/viewtopic.php?t=711130&highlight=gauge

Wed Jul 01, 2020 9:33 am

https://www.youtube.com/channel/UC_2W_OgL6dEgsA5VVBrKObA