Fuel tank question

[ricosuave420]

The other day my fuel light came on and I drove about 30 miles in town that day then I went to get gas, as I was about to make the turn on the opposite side where the station was I hit the brakes and the car died, I guess I was so low on gas and since the fuel pick up is in back of the tank so it all went to the front and it died, but I waited 30 seconds and it started right up, so I had a pretty empty tank but I filled it to the brim and I only got 14 1/2 gallons but the Manuel says its an 18 gallon tank, I was just really confused, can anyone explain this to me? Thanks

[J Wikoff]

Could be a few things.

Pump clicked off early.
Fuel strainer sock has fallen off the pump or plugged up a bit.
Tank baffles are broken.
Fuel level sensor is reading wrong.

[ricosuave420]

Gotcha, so it is an 18 gallon tank, and I'm thinking its the fuel level sensor bc I can get 300 miles out of the first half tank then only 100-150 out of the second half, I'm hoping its just that and has nothing to do with the fuel pump bc in the last 5 months I've had the pulley belt tensioner, trans coolant line, 3 new brake lines, altinator and starter replaced and I just can't afford a fuel pump for 4-500$

[Sirius]

I'd lay money on the baffle around the fuel pump pickup being broken, based on the symptoms. The baffle is there to keep the fuel pickup submerged in gas during acceleration or braking. When the baffle cracks & breaks (this is common in those cars) it can allow the fuel pump to be starved for gas under certain conditions, depending on where/how the baffle is broken. Usually keeping the tank at least 1/2 full will prevent this from happening.

I know this from personal experience. You can't buy just the baffle, either, you have to buy the whole gas tank. I can't remember what I did to fix it, but I don't think I bought a tank. Could have, I reckon, but it was too long ago.

If you do drop the tank and have a look, you might as well replace the strainer sock as this can also contribute to the problem.

[Bob Dillon]

Gotcha, so it is an 18 gallon tank, and I'm thinking its the fuel level sensor bc I can get 300 miles out of the first half tank then only 100-150 out of the second half,

It's because the tank is oddly shaped. It's basically and "L" shape but the bottom of the "L" is very shallow. Nothing to worry about.

I concur as to the above opinion that the pump clicked off early.

[haro1225]

Both my old Bonnevilles were like that, first half of the tank didn't go as fast as the last half.

[jmulhearn]

I have a 96 Bonneville and I had to have the fuel pump replaced. So, based on my experience, if you do anything to the tank/fuel pump, etc, ALSO REPLACE THE FUEL GAGE PORTION ON THE PUMP. My fuel gauge went out a week after I had the fuel pump fixed. It is still out, only reads the firs half of the tank, then stays at the half full mark.
That leaves the question, why can't it be entirely replaced at one time and eliminate the different problems at once.

[Bob Dillon]

I have a 96 Bonneville and I had to have the fuel pump replaced. So, based on my experience, if you do anything to the tank/fuel pump, etc, ALSO REPLACE THE FUEL GAGE PORTION ON THE PUMP. My fuel gauge went out a week after I had the fuel pump fixed. It is still out, only reads the firs half of the tank, then stays at the half full mark.
That leaves the question, why can't it be entirely replaced at one time and eliminate the different problems at once.

On my previous '99 BVille, I bought the cheapie Chinese sender from Rock Auto, rather than the $300 Delco unit. About $75, worked fine for over 100K.

[SSEBonne4evr]

I have a 96 Bonneville and I had to have the fuel pump replaced. So, based on my experience, if you do anything to the tank/fuel pump, etc, ALSO REPLACE THE FUEL GAGE PORTION ON THE PUMP. My fuel gauge went out a week after I had the fuel pump fixed. It is still out, only reads the firs half of the tank, then stays at the half full mark.
That leaves the question, why can't it be entirely replaced at one time and eliminate the different problems at once.

On my previous '99 BVille, I bought the cheapie Chinese sender from Rock Auto, rather than the $300 Delco unit. About $75, worked fine for over 100K.

Did the cheapie pump make noise above the OEM levels?