fuel sending unit
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Junior User
Joined: Nov 2007
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fuel sending unit
So i just got back from a trip to the dunes and before i left my fuel guage was normal but after i got back it stays at full all the time. it goes down when i turn the truck off like normal but other then that is will stay at full. anyone else have this problem and what is the easiest way to fix it??
Hotshot
Joined: Nov 2006
Posts: 11,288
Likes: 269
From: North of Greenville
Not an unheard of problem. With diesel's propensity for absorbing moisture, the metal parts on the sending unit assembly corrode fairly quickly. Mine was covered with rust when I went into my tank this summer, and it is three years younger than yours.
Solution. Run the tank (based on mileage, of course) until you think you'll run out of fuel.
Then, connect a piece of tubing (1/4 inch, I believe) to the metal tube running down the front of your engine from your fuel filter housing drain.
Put the tubing into a 5 gallon bucket.
Open the drain valve on the back of the filter housing.
Start cycling the fuel pump without starting the engine until it pumps the tank empty.
Drop the tank.
Disconnect the fuel filler hoses and wire connector.
Remove the top plastic ring and carefully take out the sending unit.
Perfect time to do the in-tank mods. Check out this link...
http://guzzle.rbmicro.com/hutch.html
Before you start, I would purchase the in-tank mod kit from this site....
http://www.itpdiesel.com/store.php?c...on=show_detail
Solution. Run the tank (based on mileage, of course) until you think you'll run out of fuel.
Then, connect a piece of tubing (1/4 inch, I believe) to the metal tube running down the front of your engine from your fuel filter housing drain.
Put the tubing into a 5 gallon bucket.
Open the drain valve on the back of the filter housing.
Start cycling the fuel pump without starting the engine until it pumps the tank empty.
Drop the tank.
Disconnect the fuel filler hoses and wire connector.
Remove the top plastic ring and carefully take out the sending unit.
Perfect time to do the in-tank mods. Check out this link...
http://guzzle.rbmicro.com/hutch.html
Before you start, I would purchase the in-tank mod kit from this site....
http://www.itpdiesel.com/store.php?c...on=show_detail
Lead Driver
Joined: Oct 2004
Posts: 7,413
Likes: 1
From: Columbia, MO
Could be a bad sending unit, a short in the wires, or the float could be wedged to the top of the tank. I had mine get wedged into the top of the tank once and it did just like yours.
If you pull the plug from the top of the sending unit and ohm the actual sending unit, it should be reading 140-160 Ohms to be reading full. If you get that reading, you'll need to drop the tank and see if the float is stuck in the up position. If it's not, the sending unit is bad.
If you get a lower reading than that, and know your fuel level is lower than full, the sending unit is probably reading correctly and you have problems further down the line.
If you pull the plug from the top of the sending unit and ohm the actual sending unit, it should be reading 140-160 Ohms to be reading full. If you get that reading, you'll need to drop the tank and see if the float is stuck in the up position. If it's not, the sending unit is bad.
If you get a lower reading than that, and know your fuel level is lower than full, the sending unit is probably reading correctly and you have problems further down the line.
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