Fuel gauge problem

power goes through the gauge down to the sender unit ,through the resistance to ground
what you have indicates a short in the wire after the gauge and before the sender unit

The fuel level sending unit inside the fuel tank is bad or the gauge is or there is a wiring problem This video is for a mercury vehicle , but all makes an models are the same . Repairing Fuel Gauge Problems 2004 Mercury Marquis EricTheCarGuy

heat gauge indicate hi temp, coolant leaking on ground below engine, coolant over flow tank constanly low, noise coming from pump body

Fuel gauges are not meant to be precision instruments. You might want to fill up a 2 gallon can and drive the car until it runs out of fuel to see how low the gauge will go before it's really empty. Use the 2 gallons to get back to a filling station.
I once spent three working days trying to get a 1972 Chrysler to read full when it's full, half when it's half and quarter tank when the tank has a quarter amount of fuel. The customer did not want to accept anything else, but in the end all I did was to get close, not exact.
It is possible that the fuel float in the gas tank is "drowned", that is, the plastic float might have a slow leak and some fuel found its way inside. This will cause the float to submerge slightly and give you a low reading. To check this you will have to remove the float unit from the tank.
In any case, if you feel up the job (not easy) remove the float unit from the tank and manually move it up and down while checking the meter reading. You can bend the wire holding the float to correct misreadings.
Personally, I wouldn't bother, just be aware that when the reading is low, feel safe that you still have enough fuel to get to the next filling station.

when a tank is empty there is no fuel for the pump and the system runs low on fuel pressure Going up hill the fuel runs away from the pick up line and the pump sucks air
After filling it takes a while to empty the air out of the system to allow full pressure again. It is an extremely costly practice to run so low on fuel as it may lead to a pump replacement

Camshaft position sensor causing random misfire. Stuck EGR valve or clogged EGR ports.

Please comment on my info.

The fuel level indicating system is a magnetic type system, which consists of the sending unit located in the fuel tank, an anti-slosh module located on the back of the instrument cluster, and a fuel gauge located in the instrument cluster. The sending unit changes resistance according to the level of fuel in the fuel tank, which varies the current flow through the gauge.The pointer position varies proportionately to the current flow. In this system, the sending unit resistance is low (22 ohms) when the fuel level is low and high( 145 ohms) when the fuel level is high. The pointer of the magnetic gauge remains in position when the ignition is turned to the Off position. On some models, an anti-slosh module is used to dampen out fluctuating fuel signals from the sender. Some vehicles are equipped with a low fuel warning indicator. The anti-slosh module will also actuate the low fuel indicator when the fuel level in the tank reaches 1/16 to 1/8 full.


Do your other gauges/warning indicators work properly with the ignition on? If not, check for power at the fuse panel/fuses.

If they do then partially remove your cluster with connector still installed and check for voltage at cluster connector and gauge. Check continuity of cluster and gauge for ground.

Sometimes the anti-slosh module (if installed) goes bad in the Grand Marquis but not likely.

Sender troubleshooting:

1. Perform test with resistors as follows:

1. Disconnect wiring connector at sender unit, then connect resistor between gauge lead and a suitable ground.
2. Turn ignition switch to On position.
3. With 145 ohm resistor, the gauge pointer should contact the Full mark.
4. With 22 ohm resistor, the gauge pointer should contact the Empty mark.

1. Perform test with fuel sender of known quality as follows:

1. Turn ignition to Off position.
2. Disconnect wiring connector from sender and connect it to test sender.
3. Move float rod away from fuel filter against Full stop position. Wait approximately 30 seconds, then turn ignition switch to On position. The gauge should read on or above the Full mark.
4. Move float rod toward fuel filter against Empty stop position. Turn ignition switch to Off position. Wait approximately 30 seconds, then turn ignition switch to On position. The gauge should read on or below the Empty mark. If gauge works properly replace sender, which involves dropping fuel tank.
   

try spraying starting fluid in air intake or throttle body. If it starts, it is a fuel problem. Can you hear ful pump run for 5 seconds when you turn key on? Pump is in tank.

go here too

http://groups.yahoo.com/group/villagerquest/

This is a normal concern.
The instrument cluster uses 4 different operating modes to calculate the fuel level:
Anti-slosh (default mode)
Key OFF fueling
Key ON fueling
Recovery
After a fuel fill up, the time for the fuel gauge to move from empty (E) to full (F) ranges from 2 seconds to 55 minutes depending on which operating mode the fuel gauge is in.
The default fuel gauge mode is called the anti-slosh mode. To prevent fuel gauge changes from fuel slosh (gauge instability due to changes in fuel sender readings caused by fuel moving around in the tank), the fuel gauge takes approximately 55 minutes to go from empty (E) to full (F).
The key OFF fueling mode (2 seconds to read empty [E] to full [F]) requires 3 conditions be met:
The key must be in the OFF position throughout the entire refueling of the vehicle.
At least 15% of the vehicle's fuel capacity must be added to the fuel tank.
The instrument cluster must receive a valid key ON fuel sender reading within 1 second of the key being put into the RUN position. The key ON sample readings are considered valid if the fuel sender reading is between 15 ohms ± 2 ohms and 160 ohms ± 4 ohms.
If these conditions are not met, the fuel gauge stays in the anti-slosh mode, which results in a slow to read full (F) event.
The key ON fueling mode (approximately 90 seconds to read empty [E] to full [F]) requires 3 conditions be met:
The transmission is in PARK (P).
The key is in the RUN position.
At least 15% of the vehicle's fuel capacity must be added to the fuel tank.
In key ON fueling mode, a 30-second timer activates after the transmission is put into the PARK (P) position (automatic transmissions). When the 30-second time has elapsed and at least 15% of the vehicle's fuel capacity has been added, the fuel gauge response time is 90 seconds to read from empty (E) to full (F). When the transmission is shifted out of PARK (P), the fuel gauge strategy reverts to the anti-slosh mode. The key on refueling mode prevents slow to read full events from happening if the customer refuels the vehicle with the key in the RUN position.
Recovery mode is incorporated into the instrument cluster strategy to recover from a missing fuel level input during a refueling event. Missing fuel level inputs result from intermittent opens in the fuel sender or its circuits. Recovery mode (empty [E] to full [F] approximately 20 minutes) is initiated when the following 2 conditions are met:
The instrument cluster is in the anti-slosh (default) mode.
The actual fuel level in the tank is greater than what is being displayed by the fuel gauge

id say either your sender unit is nackered or you have a bad earth to the body