my 87 came stock with a 3 gauge (speed, temp, and fuel) which was swapped out by the p/o with what he claimed to be a 89 SR5 4 runner cluster. it has oil pressure, tach, cool temp, speed, fuel, and voltage. it's the gauge cluster with the graph paper background

the fuel gauge is the only thing not working properly. when it hit's 'E' it still has 4.5 gallons left in it and won't budge from 'F' until aprox 3 gallons have been used.

why is this? what can i do to correct this?

 

The gauges should interchange with each other. Did it work correctly before? I have seen the fuel sending unit really corroded up or if you remove the cover on the variable resistor on it, the wire is nearly as fine as the human hair. Most cases the wire is worn thru and broken.

If you cant get it cleaned up from all the rust on it, about the only thing to do is to replace the unit.

Here is what one of mine looked like and it is after I cleaned it. Luckily the wire inside it was not broken.

 

Wow that still works much better then any of mine

These things are old I would not trust these fuel gauges in any case

All the Toyota`s I have I refuel @125 miles That is @ 10 gallons I don`t run out and keep the fuel pump in fuel.

About the best thing you could do is get a Aftermarket sending unit and gauge if it needs to be really accurate