Hi guys,
I am new to the ranger world. My 1988 truck's fuel gauge needle drops from full quickly; I am not sure if there is something wrong with the gauge or it is normal behavior for this old trucks. For example, after 23 miles the needle sits between full and 3/4. At this cadence, at half tank it will be 92 miles, which is half what it should be. Any thoughts?

 

i get around 12 miles to the gallon, very rarely over that, my needle drops at almost the same rate. When you fill up how many gallons are putting in? if your gauge says empty but you only put in, let's say 10 gallons, your gauge is dying or your sender is. but if you fill the tank and put in 14 or 15 gallons, (My numbers depend on how big your tank is) then you are just getting bad gas mileage.

 

I put about 5 gallons when the gauge marks slightly less than half tank and with 57 miles driven with a full tank.. It seems like the gauge is giving me a bad reading. Apparently is giving me about 11 MPG, which seems to be low.

 

yeah that don't seem right, most of the time it's the sending unit, i'm not completely sure how to diagnose which one is giving the bad reading.

 

The sender works as a variable resistor with the float arm sliding a contact over the surface. Old gas can deposit a varnish over things that can cause a bad reading. Before you tear into it I would recommend that you fill it up and add a fuel system cleaner. In my case it fixed my inaccurate reading gauge.