So, a while ago I ran out of fuel, the gauge was lighted, but i should of had much more than mileage than i got.

I notice today, that when i filled it today that the gauge would move up, but the light stayed on. The gauge did take a while to move to the accurate level. Any ideas on where to start? The sender is in the fuel pump, correct?

Is there an electrical component I should be looking for?

Thanks in advance.

 

My fuel gauge also has accuracy issues - it will only ever show about 75% full, even if the tank is topped off. I suspect there's an issue with the float, which is part of the fuel pump assembly. It will still go down and eventually illuminate the low fuel warning light, but I usually use the trip odometer to track when to fill up. I have a new fuel pump, just haven't installed it yet as this isn't a huge deal.

Here's how it works. If the fuel gauge is going up but the light is staying on, that suggests an electrical issue, whereas my issue where the fuel gauge never hits full sounds more like a mechanical issue with the float.

 

I notice my fuel gauge is not accurate if I leave the key in the ON position while filling the gas... Only in that instance does it take a while for the gauge to go to full. This does not happen if I turn the ignition completely off and remove the key to fill up.

 

Thanks, that is very interesting. I am not sure it is worth messing with, unless this indicates a potential pump failure is imminent. I did run out of fuel a while back when the gauge showed i should of had enough to atleast get to the gas station. luckily that was the only reason it would not run. .

 

l've noticed this too, kind of weird...it's like the ECM doesn't want to change signal to dash cluster/fuel guage until cycled or enough drive ti e has happened.

 

The float and pump are to seprarate circuits/systems on the assembly. One should not affect the other. So, float being wrong will not predict failure of fuel pump.

 

does the ECU monitor this signal, or is it direct analog to the gauge?

 

It goes to the ECU then to the gauge. The ECU reads the sending unit instantaneously, but the gauge displays the average level taken over time, this is why it takes 5-10 min to show full if you leave the ignition on while filling. If it didn't do this, the needle would be constantly bouncing around as the fuel sloshed back and forth in the tank.

 

So these all sound like electrical issues, my fuel gauge sounds like it might be mechanical. I can fill the tank, and I have full indication. However, I travel between 60-90 miles before the level begins dropping. Bent float arm? Pump assembly replaced by PO.

Rhys Legge

 

Actually, it could be the BCM (Body Control Module)...but, it's one or the other. Personally, I've not seen an analog cluster in years.

Like mentioned by RedX, much better fuel guage stability with new method of monitoring.