Gas gauge issue/question

[offroadkid]

I have noticed that after a fill-up and then 20 miles of driving the gauge shows 3/4 of a tank. That seems odd to me. Also, the gauge seems to drop rapidly and shows Empty (without light) and still has approx 5-10gallons left?? Is this common? I know the LC doesn't get the best mileage but?
OH, my LC is an 04 with 65,000,the only engine mod is the TRD air filter.
any and all suggestions would be helpful.

My recently acquired 98 does the same thing! I wil fill it up, and it won't go all the way to full. Then, afterapprox. 30 miles, it shows only 3/4 tank left.

When it gets low, the light does come on as designed.

Did you ever find a reason, or a repair?

 

[soberman001]

Nice thread.

Just a bit of history/background on why the "law" says you have to turn off the engine when filling.

Back in the day, prior to cat-converters, emission controls, vapor recovery and side-fill gas inlets, there was a chance that a spark could fly out the exhaust and light the vapors. It was very very rare, but possible since the exhaust could be as close as 12inches from the gas nozzle when stashed under the license plate of a average sedan. This spark could also cause brush fires when driving an off road vehicle through really dry grass. Again, very unlikely, but possible.

In the late 70's and mostly 1980's crash protection dictated moving the gas fill to the side of the car, and emission controls such as cat-converters make it virtually impossible for sparks or rich fuel vapors to get out the exhaust tip. So.. we are stuck with stupid signs that never get updated for today's modern car.

It will be funny 25-50 years from now if we are on full hydrogen or electric cars. The filling stations of the future will probably still have those dumb signs just in case the water or plug catches on fire.

 

[Texasoil]

All auto gasoline tanks have a 'vapor space' built in that cannot be filled with gasoline, even by 'topping off. the vent to the charcoal canister exits from this guaranteed 'vapor space.' 'Topping off' CAN completely fill the rest of the tank, including 'expansion space' designed into the fill pipe-which allows the gasoline to heat up and expand without over-pressuring a(nd potentially forcing liquid up into the vapor space and charcoal canister.)

To my knowledge , routinely 'topping up' is discouraged to avoid spillage and the resulting emissions.

 

[offroadkid]

Just an update to my earlier gas gauge post.

I had the fuel level sender replaced last week under warranty, and now when I fill the tank up, the gauge shows it full now. It used to only go just under the mark by the "F".

Also, it doesn't drop down to 3/4 tank after only 25 miles.

 

[9toys]

Get rid of the TRD air filter.
Stay with OEM.

 

[FATrabbit]

Get rid of the TRD air filter.
Stay with OEM.

Why? What about K&N?

 

[spressomon]

Why? What about K&N?

K&N breathes better but is less effective at collecting dirt particles (that's why it breathes better ). If maxing engine life is your objective I would stay with OEM type filter media. And, in spite of what K&N advertises, I don't think (based upon others on this board that have tried the K&N air filter) you'll feel or detect a MPG difference anyway...

 

[KlausVanWinkle]

Reviving an old thread here too.

When I fill up the needle drops to 3/4 of a tank after as little as 10 miles.

This time it dropped from 3/4 to 1/4 over night.
I've driven 30 miles since then and now it's on Empty and the low fuel light is on.

So either I've used 20+ gallons to drive 100 miles, my tank is leaking or something is wrong with the gauge.

I'm going to fill it up after work and see what happens.

Someone on here replaced their fuel gauge signal sender or something under warranty and it fixed a similar issue. Does anyone have details and cost on how to do that?

 

[OregonLC]

When I fill up the needle drops to 3/4 of a tank after as little as 10 miles.

This time it dropped from 3/4 to 1/4 over night.
I've driven 30 miles since then and now it's on Empty and the low fuel light is on.

So either I've used 20+ gallons to drive 100 miles, my tank is leaking or something is wrong with the gauge.

I'm going to fill it up after work and see what happens.

Someone on here replaced their fuel gauge signal sender or something under warranty and it fixed a similar issue. Does anyone have details and cost on how to do that?

Is your neighbor's kid home from college for the holidays? Sounds like someone thinks the LC is a tanker.

 

[KlausVanWinkle]

Is your neighbor's kid home from college for the holidays? Sounds like someone thinks the LC is a tanker.

No kids anywhere. Everyone here is old and retired or 25-35 yuppies (that might be self incriminating)

I filled up last night and it took the normal amount to fill up the tank. So either I was wrong and my memory failed me or my tank has a massive leak. I think it's the former.

 

[socalmtbiker]

Reviving -

Notice that my gauge was a bit finicky since I bought the rig. The gauge would drop only quickly over a few miles after filling up. Then when I refill at a quarter tank left, it would take about 14gallons to fill. Yesterday I let it hit E, no warning light. The estimated miles left to drive on the nav said 36miles. I drove about 10 more miles on E, still no light. Got to the gas station and it took 20gallons to fill.

Based on some threads I guess it's the sender. Anyone know how difficult it is to replace or any other possible solution?

 

[Live to Ski]

As an aside, this is what I have read from the HIH forum:

newer 100 series cruisers (2000+?) relocated the charcoal canister lower. In heat at altitude, overfilled tank causes vapor lock (after reading a bunch on this, still don't understand). Current thought is to fill no higher than 3/4 tank to avoid charcoal saturation.

Not sure how this relates to overfilling @ stations, but sounds related.

 

[jerryb]

for future searches. I found this by accident. looking for engine oil/pressure sender.

picture is self explanatory to most I assume.

 

[TrekboxX]

Nice thread.

Just a bit of history/background on why the "law" says you have to turn off the engine when filling.

Back in the day, prior to cat-converters, emission controls, vapor recovery and side-fill gas inlets, there was a chance that a spark could fly out the exhaust and light the vapors. It was very very rare, but possible since the exhaust could be as close as 12inches from the gas nozzle when stashed under the license plate of a average sedan. This spark could also cause brush fires when driving an off road vehicle through really dry grass. Again, very unlikely, but possible.

In the late 70's and mostly 1980's crash protection dictated moving the gas fill to the side of the car, and emission controls such as cat-converters make it virtually impossible for sparks or rich fuel vapors to get out the exhaust tip. So.. we are stuck with stupid signs that never get updated for today's modern car.

It will be funny 25-50 years from now if we are on full hydrogen or electric cars. The filling stations of the future will probably still have those dumb signs just in case the water or plug catches on fire.

I fill up all the time with the motor running, and have for years. As long as you dissipate any static away from the vapors around the filler, you won't likely explode.