2005 Malibu fuel gauge problem
 

hi, ive noticed some similar problems around the forums, but no responses to them.. i just hope someone can help me with this one.

recently, after i fill up my car about a minute or so into the car being on, the fuel gauge drops from full to empty, and sometimes the check engine light comes on. But after maybe an hour of driving (or less i haven't actually timed it) the fuel gauge is back up to full and starts to function as it should. this only happens when i fill up when the low fuel light comes on, it doesn't happen when i fill up from 1/4 tank or above.

thanks for any help you guys can give, i really don't want to take it into a dealer...

I would first check all in wires and connections to the sending unit. If they are all good I would change the sending unit.

2005 Malibu Fuel Level Sender Fix - Beating the System
 

2005 Malibu Fuel Level Sender Fix - Beating the System

One day the fuel level sender in my 2005 Malibu failed, alternating from full to empty, and causing my
check engine light to come on. I chose not to fix it for a while - given the
cost and hassle - and just calculate fuel use by mileage. I figured,
why bother going through all the hassle of dropping the tank and
changing the sensor if my fuel pump is still good?

Well, some months passed and the car came due for inspection. I live
in Massachusetts and to get the car to pass inspection, no error codes
can be present in the computer. Here's what I did to make it pass
inspection for under $2: Trick the computer with a 100ohm 1/8 watt
resistor from Radio Shack. Here's how I did it:

At the fuel tank electrical connector block under the car near the
tank, find the purple wire (fuel sender) and the black wire (ground).
In the back of the connector (the side which leads up to the front of
the car, NOT the side that leads to the tank), take a sewing needle or
small awl and clear paths for the resistor leads to slide in past the
wire seals and make contact. Carefully slip the 100ohm 1/8th watt
resistor into the spaces next to the wires, connecting the purple and
black wires with the resistor. Next, open the connector and check with
a multimeter that there is continuity between the connector pins and
the resistor leads on the back of the connector. Reconnect and turn
the key to the on position. The fuel gauge should now be reading about
1/4 tank - a reading it will have permanently. To finish the job, put
some RTV silicone on the contact points of the resistor and plug to
keep water out. Blast the code from the computer if you want. If you
ever change the sender, remember to take the resistor out!

Disclaimer: Enjoy this cheap fix, and understand that I take zero
responsibility for the information, and do not recommend that you
actually do this."

Keep it real,

-M@