2005 fuel gauge stuck on full

[Good Lookin Bob]

I have a 2005 Thunderbird that just turned 40k miles and runs beautifully. The gas gauge registers Full almost all of the time. As the tank(s) get near empty, the gauge drops to Empty. At that time it is a race to the gas station to get get 17-18 gallons of gas. Has anyone else had any experience like this? It is my understanding that the sensors are attached to the fuel pump. If I have to pull the pump to change the sensor, I might as well install a new pump while I am there.

So let me ask a few questions.
1. Will a new passenger side fuel pump likely fix this problem?
2. How much should a quality fuel pump cost? Right now on Amazon fuel pumps range from $60 to $100 dollars. Are those prices correct, or are they just all from China?
3. Should I change the Fuel Filter as well at the same time?

Keep in mind this car runs beautifully except for a malfunctioning fuel gauge.

Thanks for you time and expertise.

 

[BAC]

I have a 2005 Thunderbird that just turned 40k miles and runs beautifully. The gas gauge registers Full almost all of the time. As the tank(s) get near empty, the gauge drops to Empty. At that time it is a race to the gas station to get get 17-18 gallons of gas. Has anyone else had any experience like this? It is my understanding that the sensors are attached to the fuel pump. If I have to pull the pump to change the sensor, I might as well install a new pump while I am there.

So let me ask a few questions.
1. Will a new passenger side fuel pump likely fix this problem?
2. How much should a quality fuel pump cost? Right now on Amazon fuel pumps range from $60 to $100 dollars. Are those prices correct, or are they just all from China?
3. Should I change the Fuel Filter as well at the same time?

Keep in mind this car runs beautifully except for a malfunctioning fuel gauge.

Thanks for you time and expertise.

Yes, same issue for me ... 41k miles on a 2005 T bird. I had a mechanic who speciallizes in such cars change out the fuel pump. He did and it went out on his test drive. He installed a different pump at his cost and all is good for now (fingers crossed.) Not cheap ... fuel pump aseembly passenger side $464. My car runs and rides beautifully as well!

 

[Good Lookin Bob]

Yes, same issue for me ... 41k miles on a 2005 T bird. I had a mechanic who speciallizes in such cars change out the fuel pump. He did and it went out on his test drive. He installed a different pump at his cost and all is good for now (fingers crossed.) Not cheap ... fuel pump aseembly passenger side $464. My car runs and rides beautifully as well!

Thank you very much, BAC

I do see that the new pump assemblies at Advance, Autozone, NAPA, and O’Reiliey’s, and are all $220 to $400. I wonder if they are the same cheap pumps that are found on Amazon and are just marked up double the price.

Thanks.

 

[gregl32]

There are two sensors, one on each side of the tank. The signal from both is combined to show fuel level at instrument panel gauge. I believe there is a diagnostic chart describing how the gauge will react if one sensor is bad. I don't remember exactly but it's something like if the driver side sensor is bad the gauge will only show half full even when full or if pass side sensor is bad the gauge will never go below half. It's something like that. If you get access to the tank you can try disconnecting the sensors one at a time and see if gauge responds. The driver's side pump/sensor is unobtanium except maybe junkyard. Unfortunately I haven't been able to source the actual sensors (they bolt on to the pump assembly), but there may be some companies out there that can rebuild them depending on what's wrong, I don't know for sure though.

 

[JoseG]

In the past I had luck on some of my previous vehicles by adding Marvel Mystery Oil to the fuel, sometimes the
fuel will create a film on the fuel sensor or fuel sending unit and it won't read properly, it would fluctuate this could easily happen if the fuel stays in the tank for too long.

 

[Gunther10]

In the past I had luck on some of my previous vehicles by adding Marvel Mystery Oil to the fuel, sometimes the
fuel will create a film on the fuel sensor or fuel sending unit and it won't read properly, it would fluctuate this could easily happen if the fuel stays in the tank for too long.
View attachment 31050

Greetings gentlemen. A search in the forum should reveal that ChevronTechron fuel additive has a chemical that apparently helps keep the contact points of the sensors on the fuel pump clean of deposits leading to accurate fuel guage readings

 

[doug7740]

I would start by checking for fault codes in the instrument cluster. Instrument cluster DTC B1202 will set if the fuel sender circuit is open or shorted to power. Instrument cluster DTC B1204 will set if fuel sender circuit is shorted to ground. Instrument cluster DTC B2627 will set if the jet pump sender circuit is open. Instrument cluster DTC B2628 will set if the jet pump sender circuit is shorted to ground. Instrument cluster DTC B2879 will set if the fuel level measured by the jet pump module is greater than the fuel level measured by the fuel delivery module. A Rear Electronic Module DTC B1201 will be set if either the fuel pump delivery or jet pump module is out of range or if the data reading is invalid.

Depending on the fuel level on the fuel pump delivery module side of the tank, if the jet pump module is open, the fuel gauge will default to the fuel pump delivery module value and the fuel gauge will indicate E to 1/2 tank. If the fuel delivery module is open, the fuel gauge will default to the empty position.

doug7740
1955 Thunderbird Blue