aga

heya guys. So, my low fuel light doesnt work. pulled the fuel pump assembly, i ground the fuel light sensor to the ground, the dash light comes on. i get another pump assembly and sensor, try the other sensor doesnt work either.

the sensor is the 1-2cm long cylindrical thingy , right? how do these things even work? i opened up one and it has something that looks like a resistor inside, that connects the arm to the body around it.

what should i do? i know the fuel light is nothing important but i want everything in my car working ...it eats me up inside

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My Build

No 240.. No id

The fuel light is helpless. It only work when you are extremly out of gas or when your car is about to cut off. It pretty much works when it gets below E.

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You can sleep in your car, but you can't drive your house.

aga

as soon as i hit E i'm outta gas lol.

if i ground the sensor's wire to the chassis, the dash light comes on, so wiring is ok. but neither sensor works.... i dunno.

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jakemkz

If you are out of gas when the gauge is on E then there may be an issue with your float or fuel pump mount (pickup location). I believe the 240 has at least 1 gallon reserve, so the gauge should go below E. After running completely out of gas how much do you put in to fill it up? From the 1992 FSM the fuel capacity is 15 7/8 gallons (60L).

aga

now that i think about it, i may didn't run out of gas. I'll explain:

i am driving, the needle is at E. the car makes a pop out of the exhaust, and idles, the wideband shows 00 (lean, running on fumes) ...i coast for 100m, and park on the side of the road, and then the car dies. i take my trusty old fuel canister, walk a mile to the gas station, and come back and fill up the car. When i try to start it, i realise i'm not hearing the pump. i check the fuse, blown. i think, when the pump ran dry, it sucked too much power and blew the fuse. it's a usual thing with walbro pumps to need a bigger fuse.

anyway i replace the fuse and drive off. 10 days later, with a full tank of gas, the fuse blows with no reason on the highway. After that, i changed the wiring to the pump, with a bigger line and an extra relay near the pump and blah blah.

so yeah, it might have just been a blown fuse and not ran out of gas.

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jakemkz

Alright, well if that is the case perhaps the light will work when the tank is truly empty. The low fuel light in my 92 works but it does not illuminate until the fuel level is well below E. It is also possible that the arm which touches the resistive scale on the fuel level sending unit is bent, causing the gauge cluster to read high, this would also explain why you ran out of gas while the gauge was at E. I have extracted a portion of page EL-59 of the 1992 240SX FSM for you.



edit: By the way, the low fuel light switch is between pins C and E in this diagram (C is directly above pin G). When these pins are connected the low fuel light will turn on. Good luck.

aga

thanks for the diagram. i did remove the whole assembly and the light didnt turn on even when it was exposed to the air...

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My Build

Primo's Silvia

My low fuel light likes to play peeka-boo -.-
Sometimes its bright and sometimes its really dim and nearly visible and sometimes it never comes on -.-
So i just dont play the guessing game when im on E -.-

jakemkz

It may be worth inspecting/cleaning the chassis grounds for the main harness. The schematic for a 92 (FSM Page EL-61) shows that the light is grounded through body grounds M101 and M125. These are inside the trunk on the back wall (M125) and on the LH frame rail under the rear seat (M101). These have probably never been cleaned in most S13s which are now over 20 years old (in the US). For illustrations of the locations see page EL-110 of the 1992 240SX FSM.