Fuel guage question..

[Mr Twigbert]

My Aztec's fuel guage is acting funny..

When I start the car it seems most accurate and appeares to read accurate.. But when I start to drive it moves around alot and never goes below 1/2 a tank.. When I fill up it always stays between 3/4 and full.. However, once it get's low on gas it starts to bounce around alot.. Depending on the road it can go from 1/2 to full.. This means I am low on gas so I fill up..

What do you think could cause this?

[brotherbenn83]

I'd have to guess worn contacts on the fuel level sensor. Fuel level sensors are nothing more than a resistor with an arm attached to a float that sweeps up and down as the fuel level changes. A lot of them read from 40-240 ohms. If there is a spot where it goes OL (out of limits/open) it can cause erratic fuel gauge readings. My guess is if you had the PCM scanned you would find a P0463 Fuel Level Sensor Circuit High Voltage DTC.