Fuel light on/guage empty but still 11litres in the tank?!

[WinstonWolf]

S0 What said:

Riff Raff said:

WinstonWolf said:

littleredrooster said:

WinstonWolf said:

Any crap that gets in the tank will sit at the bottom, 11 litres isn't that much spread over a large tank and you don't really want it getting into the fuel lines/filter.

It's done by design to help stop the numpties from blocking their fuel systems up.

So you think fuel is drawn from the top of a tank? Really?

http://www.subaruforester.org/vbulletin/f88/06-forester-xt-replacing-fuel-pump-fuel-filter-110334/

I think that link just shows that littleredrooster is right. The fuel pick up is at the bottom of the tank. The fact that the pick up pipe / pump / filter assembly exits at the top is neither here nor there.

Of course the pick up is at the bottom, it would be pretty dam useless at the top (not aimed at you but at the pratts who think letting the tank run low allows crap to be sucked up).
Fuel senders wear out or rather the tracks do and as they wear the resistance alters, some last decades some years, usually the fuel light is a seperate track so there can be differences in the 2 but usually the light comes on with 2 gallons left on jap motors IME but look in the handbook to check.
Over the last year i've changed probably 20 fuel pumps and or removed them to remove a missfuel, out of all of them the only cr@p i've found in a tank was diesel mould (turns the fuel black and blocks filters), plastic tanks simply dont get as crappy inside as steel ones used to, that's why they are made of plastic nowdays, i've yet to find a tank that's full of particulates from tesco petrol stations (insert the supermarket you hate in leu of tesco).
The main reason modern pumps pack up is running out of fuel overheats them, wears the rotor tips/siezes them.
Lastly, never come accross a car that will put the engine light up for a non working fuel gauge, the managment light sould only illuminate for an issue that affects emmisions, not that i've worked on every car,, yet.

http://www.finelinefuelsystems.com/fuelsystem.html

[Ari]

hora said:

TimmD said:

Of the various Subarus I've had, all did this. I just learnt that the real empty line in near the bottom the 'E' on your picture...

This means rather than getting circa23mpg av I'll be getting 27mpg out of my shonky driving. With a more careful rightfoot it'll be 32ish average on my European Trip in a weeks time

Given that the only reliable way to calculate MPG is to fill it, use it, fill it again and calculate how far it went on the fuel used up (the miles per gallon), how can what is left in the tank possibly be relevant?

If you brim it and then cover 300 miles and filling it back to brim takes 10 gallons then you are achieving 30mpg. That's irrespective of whether there was a litre left or 100 litres left - you've still used the same amount of fuel to cover the same distance surely?

[Ren Esis]

What are these contaminates that you speak of out of interest?

I always thought this was an issue in the 60s/olden days with their non-treated metal fuel tanks, and the insides used to rust causing fuel pipes to get clogged? I would of thought modern fuel is pretty clean also.

[WinstonWolf]

Ren Esis said:

What are these contaminates that you speak of out of interest?

I always thought this was an issue in the 60s/olden days with their non-treated metal fuel tanks, and the insides used to rust causing fuel pipes to get clogged? I would of thought modern fuel is pretty clean also.

Not all fuel is as clean as ours, imagine refuelling in the third world or the outback.

[FD3Si]

I hate the idea of all those non existent particles getting into my fuel filter. They need to bugger off and let it get on with it's job of filtering fuel.

Wow, what a thread about a non issue with a side helping of nonsense. I'd rather a pessimistic gauge than an optimistic one!

[S0 What]

WinstonWolf said:

S0 What said:

Riff Raff said:

WinstonWolf said:

littleredrooster said:

WinstonWolf said:

Any crap that gets in the tank will sit at the bottom, 11 litres isn't that much spread over a large tank and you don't really want it getting into the fuel lines/filter.

It's done by design to help stop the numpties from blocking their fuel systems up.

So you think fuel is drawn from the top of a tank? Really?

http://www.subaruforester.org/vbulletin/f88/06-forester-xt-replacing-fuel-pump-fuel-filter-110334/

I think that link just shows that littleredrooster is right. The fuel pick up is at the bottom of the tank. The fact that the pick up pipe / pump / filter assembly exits at the top is neither here nor there.

Of course the pick up is at the bottom, it would be pretty dam useless at the top (not aimed at you but at the pratts who think letting the tank run low allows crap to be sucked up).
Fuel senders wear out or rather the tracks do and as they wear the resistance alters, some last decades some years, usually the fuel light is a seperate track so there can be differences in the 2 but usually the light comes on with 2 gallons left on jap motors IME but look in the handbook to check.
Over the last year i've changed probably 20 fuel pumps and or removed them to remove a missfuel, out of all of them the only cr@p i've found in a tank was diesel mould (turns the fuel black and blocks filters), plastic tanks simply dont get as crappy inside as steel ones used to, that's why they are made of plastic nowdays, i've yet to find a tank that's full of particulates from tesco petrol stations (insert the supermarket you hate in leu of tesco).
The main reason modern pumps pack up is running out of fuel overheats them, wears the rotor tips/siezes them.
Lastly, never come accross a car that will put the engine light up for a non working fuel gauge, the managment light sould only illuminate for an issue that affects emmisions, not that i've worked on every car,, yet.

http://www.finelinefuelsystems.com/fuelsystem.html

That link is about carb fuel systems (canadian carb fuel systems at that), an EFi system cannot tolerate the loss of fuel to the inlet as this will stall the fuel pump and hense the engine a carb engine will tolerate this as the carb
A has a fuel reserve built in (the float bowl)
B doesn't need the constant pressure of the fuel pump to continue working as a carb works on pressure differance (IE vacume) not possative pressure.
I'll get a few pics of the old pumps i've changed recenly to prove the fuel pick up is at the very bottom, not an inch off the bottom or even half an inch off the bottom, in fact most fuel pickups are below the bottom of the tank in a small sump.

I haven't seen any major rubbish in a fuel tank since i last opened up a metal tank to weld in a swirlpot, plastic tanks do not suffer from rust so are allways cleaner than old metal tanks, 99% of dirty fuel filters are clogged with water or in the case of diesels it's usually diesel bug, i've got ni-on 2 barrels (210Ltrs) of bugged diesel out back, if i ever get a diesel heater i may get some use from it ? as it is now i mix it with old engine oil and give it away to a local paint shop that has an oil fired heater.
I have had the odd one in with sand in it but they ni on allways dont have locking fuel caps/flaps so blaming the fuel station is more a guess than proof.

Edited by S0 What on Friday 19th December 21:49

[ohtari]

Just a typical subaru tbh.

The other day I drove 10ish miles on the fuel light, and only got 52l into the tank (brimmed). Given a 60l tank capacity, that's a lot of reserve!

[WinstonWolf]

S0 What said:

WinstonWolf said:

S0 What said:

Riff Raff said:

WinstonWolf said:

littleredrooster said:

WinstonWolf said:

Any crap that gets in the tank will sit at the bottom, 11 litres isn't that much spread over a large tank and you don't really want it getting into the fuel lines/filter.

It's done by design to help stop the numpties from blocking their fuel systems up.

So you think fuel is drawn from the top of a tank? Really?

http://www.subaruforester.org/vbulletin/f88/06-forester-xt-replacing-fuel-pump-fuel-filter-110334/

I think that link just shows that littleredrooster is right. The fuel pick up is at the bottom of the tank. The fact that the pick up pipe / pump / filter assembly exits at the top is neither here nor there.

Of course the pick up is at the bottom, it would be pretty dam useless at the top (not aimed at you but at the pratts who think letting the tank run low allows crap to be sucked up).
Fuel senders wear out or rather the tracks do and as they wear the resistance alters, some last decades some years, usually the fuel light is a seperate track so there can be differences in the 2 but usually the light comes on with 2 gallons left on jap motors IME but look in the handbook to check.
Over the last year i've changed probably 20 fuel pumps and or removed them to remove a missfuel, out of all of them the only cr@p i've found in a tank was diesel mould (turns the fuel black and blocks filters), plastic tanks simply dont get as crappy inside as steel ones used to, that's why they are made of plastic nowdays, i've yet to find a tank that's full of particulates from tesco petrol stations (insert the supermarket you hate in leu of tesco).
The main reason modern pumps pack up is running out of fuel overheats them, wears the rotor tips/siezes them.
Lastly, never come accross a car that will put the engine light up for a non working fuel gauge, the managment light sould only illuminate for an issue that affects emmisions, not that i've worked on every car,, yet.

http://www.finelinefuelsystems.com/fuelsystem.html

That link is about carb fuel systems (canadian carb fuel systems at that), an EFi system cannot tolerate the loss of fuel to the inlet as this will stall the fuel pump and hense the engine a carb engine will tolerate this as the carb
A has a fuel reserve built in (the float bowl)
B doesn't need the constant pressure of the fuel pump to continue working as a carb works on pressure differance (IE vacume) not possative pressure.
I'll get a few pics of the old pumps i've changed recenly to prove the fuel pick up is at the very bottom, not an inch off the bottom or even half an inch off the bottom, in fact most fuel pickups are below the bottom of the tank in a small sump.

I haven't seen any major rubbish in a fuel tank since i last opened up a metal tank to weld in a swirlpot, plastic tanks do not suffer from rust so are allways cleaner than old metal tanks, 99% of dirty fuel filters are clogged with water or in the case of diesels it's usually diesel bug, i've got ni-on 2 barrels (210Ltrs) of bugged diesel out back, if i ever get a diesel heater i may get some use from it ? as it is now i mix it with old engine oil and give it away to a local paint shop that has an oil fired heater.
I have had the odd one in with sand in it but they ni on allways dont have locking fuel caps/flaps so blaming the fuel station is more a guess than proof.

Edited by S0 What on Friday 19th December 21:49

I'm just explaining why they don't draw the fuel from the very bottom. Just because you haven't seen contaminants in the tanks you have worked on doesn't mean it doesn't happen.

In a lot of parts of the world fuel is decanted from ancient jerry cans, contamination is inevitable.

[S0 What]

WinstonWolf said:

S0 What said:

WinstonWolf said:

S0 What said:

Riff Raff said:

WinstonWolf said:

littleredrooster said:

WinstonWolf said:

Any crap that gets in the tank will sit at the bottom, 11 litres isn't that much spread over a large tank and you don't really want it getting into the fuel lines/filter.

It's done by design to help stop the numpties from blocking their fuel systems up.

So you think fuel is drawn from the top of a tank? Really?

http://www.subaruforester.org/vbulletin/f88/06-forester-xt-replacing-fuel-pump-fuel-filter-110334/

I think that link just shows that littleredrooster is right. The fuel pick up is at the bottom of the tank. The fact that the pick up pipe / pump / filter assembly exits at the top is neither here nor there.

Of course the pick up is at the bottom, it would be pretty dam useless at the top (not aimed at you but at the pratts who think letting the tank run low allows crap to be sucked up).
Fuel senders wear out or rather the tracks do and as they wear the resistance alters, some last decades some years, usually the fuel light is a seperate track so there can be differences in the 2 but usually the light comes on with 2 gallons left on jap motors IME but look in the handbook to check.
Over the last year i've changed probably 20 fuel pumps and or removed them to remove a missfuel, out of all of them the only cr@p i've found in a tank was diesel mould (turns the fuel black and blocks filters), plastic tanks simply dont get as crappy inside as steel ones used to, that's why they are made of plastic nowdays, i've yet to find a tank that's full of particulates from tesco petrol stations (insert the supermarket you hate in leu of tesco).
The main reason modern pumps pack up is running out of fuel overheats them, wears the rotor tips/siezes them.
Lastly, never come accross a car that will put the engine light up for a non working fuel gauge, the managment light sould only illuminate for an issue that affects emmisions, not that i've worked on every car,, yet.

http://www.finelinefuelsystems.com/fuelsystem.html

That link is about carb fuel systems (canadian carb fuel systems at that), an EFi system cannot tolerate the loss of fuel to the inlet as this will stall the fuel pump and hense the engine a carb engine will tolerate this as the carb
A has a fuel reserve built in (the float bowl)
B doesn't need the constant pressure of the fuel pump to continue working as a carb works on pressure differance (IE vacume) not possative pressure.
I'll get a few pics of the old pumps i've changed recenly to prove the fuel pick up is at the very bottom, not an inch off the bottom or even half an inch off the bottom, in fact most fuel pickups are below the bottom of the tank in a small sump.

I haven't seen any major rubbish in a fuel tank since i last opened up a metal tank to weld in a swirlpot, plastic tanks do not suffer from rust so are allways cleaner than old metal tanks, 99% of dirty fuel filters are clogged with water or in the case of diesels it's usually diesel bug, i've got ni-on 2 barrels (210Ltrs) of bugged diesel out back, if i ever get a diesel heater i may get some use from it ? as it is now i mix it with old engine oil and give it away to a local paint shop that has an oil fired heater.
I have had the odd one in with sand in it but they ni on allways dont have locking fuel caps/flaps so blaming the fuel station is more a guess than proof.

Edited by S0 What on Friday 19th December 21:49

I'm just explaining why they don't draw the fuel from the very bottom. Just because you haven't seen contaminants in the tanks you have worked on doesn't mean it doesn't happen.

In a lot of parts of the world fuel is decanted from ancient jerry cans, contamination is inevitable.

That still doen't alter the fact that fuel pick ups are at or below the bottom of the fuel tank, any contaminants are captured in the fuel filter.
According to your logic just cos some 3rd world countrys use jerry cans the whole world would start using a system with a fuel pickup that compromises the whole fuel system and the operation of the vehical?

[WinstonWolf]

It's not my logic, I've simply explained why manufacturers do it.

The fuel system isn't compromised, it adds an additional layer of protection.