Hi everyone new here and looking for some advice.The car has 140k on it and the fuel gauge will read just past 3/4 of a tank when completely full.I have replaced the fuel pump/sending unit with new and also replaced the passenger side sending unit with a new one.I just left the gas station again and put in every ounce of gas I could put it in as slow as you can and the gas did start to come back out.And still reads just past 3/4.Does anyone have any other ideas besides a new fuel gauge?Dont really know what else to change.Any and all help will be appreciated.

 

Does it Read Correctly at Empty?

Are You Sure the Tank is Full? You Know About the Fuel Fill Issue Correct?

Are You Familiar With Filling These cars With the Fuel Nozzle Upside Down?

That's How I Have Been Filling My Shelby Since New.

Fyi 16 Gallon Tank if you were not Aware.

Mgb,

KC

 

Shop Manual Info,Fuel Gauge

The instrument cluster (IC) receives the fuel level signal from the fuel level sensor, part of the fuel pump module. The fuel level sensor measures variable resistance in the fuel tank depending on the current fuel level. When the fuel level is low, the resistance in the unit is low (15 ohms ± 2 ohms). When the fuel level is high, the resistance in the unit is high (160 ohms ± 4 ohms).

The instrument cluster (IC) uses 4 different operating modes to calculate the fuel level:

• Key OFF fueling
• Anti-slosh (default mode)
• 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 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 (IC) 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 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 ON fueling mode (approximately 90 seconds to read empty [E] to full [F]) requires 3 conditions be met:

• The transmission is in PARK (P) (automatic transmissions), or the parking brake applied (manual transmissions).
• 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) or when the parking brake is applied (manual 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) or the parking brake is released, the fuel gauge strategy reverts to the anti-slosh mode. The key ON fueling 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 (IC) strategy to recover from missing fuel level inputs during a refueling event. Missing fuel level input 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 (IC) 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.

Mgb,

KC

 

Yes I read up on that.I tried putting the nozzle sideways and upside down and same result.Went to 2 different gas stations also sat there for 15 minutes slowly putting the gas in and I believe it is full.Should I replace the evap canister next?

 

I Would Find Somebody Who Can Pull Up {Both Body & Pcm Codes.} Should Have a Fault Code For Issue. Issue Could Be in a Number of Places. Wiring,SJB,Cluster Etc.

I would Most Concerned Where True Empty is. I would Run Fuel Low and Get a Gas Can With Two Gallons in it. Run it Dry or Pump it Out last bit When you Know its Getting Really Low Etc. and Then Put in The Two gallons and See where it Reads. That Point After the Two Gallon Fill Would Be My Empty! That is If You Want to Keep Driving While Trying to Figure Out. Just A Thought!

Mgb,

KC

 

Thanks for the help I found someone to check and see if there are any codes and will go from there.