When working with fuel system, the most important factor is to do it in a well ventilated area and keep naked flames or sparks out of the way. Keep all car doors open.
DO NOT test fuel pump by connecting wires that could produce sparks if it is taken out of the fuel tank.
The 1/4 might be the correct reading, I have yet to see any sending units out of calibration so perfectly. When fuel tank is full, it would show past the F mark.
The possible reason I can think of when you have run out of gas when the gauge is at 1/4 is the fuel pump strainer is faulty, it could be broken or detached.
To calibrate the sending unit, you need to know its lowest and highest resistance.
The low fuel warning indicator sensing unit uses a separate circuit so is not related to the gauge reading.
Thursday, July 17th, 2008 AT 9:31 AM