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waycool
12-05-2013, 02:49 AM
I have a 1993 GTS which had a dead spot on the fuel gauge. When you filled the tank, the gauge would read empty until you burned about half the tank and then it would work from there. I replaced the sending unit with a factory one and it was working fine until I got down to a quarter tank. Now my low fuel tank lights up and goes out sporadicly. This was working with the bad sending unit at the appropriate level. Does anyone know what might have changed. Do I need to pull the sending unit and adjust something. Any ideas???

METDeath
12-05-2013, 04:52 AM
When it starts coming on/off is if you fill up when it first comes, is it around a 10 gallon fill up?

If so, my experience (two 91s) says that is normal operation. However, I could more than certainly be wrong about that particular detail.

waycool
12-06-2013, 03:34 AM
On the gauge it is around a 1/4 tank line. Before the sending unit went bad, it would come on a little above the E line. That is where I think it should come on. I took apart the the old sending unit and it looks like a rheostat with the float arm moving up and down on it. Maybe Toyota screwed up on where the empty contact tied in. Any ideas.

METDeath
12-06-2013, 04:50 AM
Didn't actually answer my question.

waycool
12-06-2013, 11:51 PM
No, it is around a 9 gallon fill up. Before the change out, it would come on and then I would add 12 gallons. I thought the manual said that the gas tanks in the 5th gens were 16 gallons. I am scared to see how low I can run the needle before stalling.

METDeath
12-07-2013, 12:35 AM
I would almost say it is out of calibration, but I'm not sure if there is any calibration on the stock units.

pitcelica
12-16-2013, 03:12 AM
It happened to me. You will need to remove the fuel sending unit, open it up and you will see the kind of "wiper arm" that goes to all the printed circuit board lines. When the wiper arm moves (when the float goes up and down), the wiper makes continuity with a different circuit line and this changes the resistance.

The problem I had is that when the float is all up (full tank), the wiper arm do not touch the circuit lines anymore. This create an open circuit and the gauge show empty. You will need to place the wiper arm at the good postion. According to BGB, you should have around 3 ohms when full tank and 110 ohm when empty tank. This little wiper arm is only friction fit on his shaft, so it can be moved quite easily.

Sam

waycool
12-21-2013, 12:38 AM
Where do you read the resistance and how do I change the wiper arm. The new sending unit was a sealed plastic unit with the float attached.

pitcelica
12-21-2013, 02:14 AM
You need to check the resistance at the fuel sender connector, between pins 3 and 4, wire Yellow-Red and Brown. My sending unit isn't sealed, you simply remove the cap with two screws and you can see the inside circuitry.

Sam