Fuel gauge not working properly

NORTHPORTMAZDA

MEMBER
1991 MAZDA B2600
2.6L
4 CYL
4WD
MANUAL
137,000 MILES

My fuel gauge works, kind of. The problem is it's not always accurate. Sometimes after I fill up and I drive for a bit the fuel gauge will drop down to a half a tank pretty quickly and then sit there. And then it will eventually start going down. It always goes down faster then what I actually using fuel. Another thing it does is that after you fill the tank it takes quite a while for it to climb all the way to the full mark. I have gotten to the point where I just use the mileage for knowing when I need to get gas.

Would this be more of a fuel gauge issue or more of the float / sending unit at the tank? And what would be the simplest way to check or troubleshoot the problem?

1 Reply

SEVAG P

MECHANIC
405 POSTS

Thanks for using 2CarPros.

Fuse is probably good because gauge is working but with wrong indication, as a first step check fuel gauge connector visually for any damage or corrosion, fuel gauge sender unit is inside the fuel tank. It must be removed to perform the tests also check its connector and wires. Use ohmmeter fuel gauge sender unit connector removed, ignition on check picture 4 red lead of ohmmeter at connector pin y and the black one on pin b, check picture 1 and 2 for the tests and compare with the table specified values.
Waiting for your feed back thank you.

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