# 1990 nissan sunny B11 fuel gauge



## ashraz (Apr 8, 2019)

hi, 

recently i changed the fuel sending unit to a aftermarket (taiwan made) new unit. but the low fuel warning light is not working when running low on fuel. I noticed it does not have a metal tube at the bottom (that look like fuel temperature sensor)on the new one. is this why the low warning light sensor not working? or something else?

how does the the warning light sense the low fuel in the tank?

another question is...on the fuel gauge..how many liters does the lines represent? 


thanks in advance!


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## smj999smj (Jan 1, 2006)

In the future, you would be best to post in the B11/B12 Sentra section rather than "classic Datsun." Nissan fuel gauge sending units came with and without fuel warning sensors as it was an option on many models. If you installed a sender designed for a vehicle without a low fuel level warning, it would make sense that it is not working on your vehicle. You would have to put the correct sending unit it. As far as how many liters each line represents, I couldn't tell you. Most gauges I've seen usually have lines at each 1/4 tank, so if that's what you have, divide the fuel tank capacity by four. It wouldn't be exact, but in the general area. One really shouldn't run the tank below 1/4 tank, anyway. If you have an electric fuel pump in the tank, the fuel cools the pump and running the fuel low gives less cooling capacity, so the pump runs hotter and can shorten the life over time. Running the tank low can also cause sediment and water to be picked up into the fuel system.


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