Help; 4running out of fuel

[wfo9]

Yea, there are some people on this site that really don't know much of anything about cars, but like to bully people around because they have read things on the internet and have been here a while. LOL It's not that unusual for a site like this, but this seems much worse than most. I think most are just looking to have some fun.

Anyway, I don't really know the details of the 4Runner fuel system, but I have worked on many modern fuel systems trying to push them to the limits. There are many different things that could be at play. One thing is for sure, it has nothing to do with your exhaust or tires....

My first guess would be that you did damage the pump a bit and its overall efficiency has been decreased. What happens is that when the tank gets low the total head the pump must overcome is increased due to the increased suction head. It simply can't create enough pressure up at the fuel rail anymore and needs to be replaced.

Another guess would be that the sock/filter in your tank is clogged. They all get gunk in them, but you may have had a really dirty tank that again is creating more head pressure for the pump to overcome when low.

The calibration on the float could be off giving you a higher reading than reality, but that is not a common problem.

Finally, some systems have an inner canister that acts as a sump for the pump. They usually use a venturi effect from the return to suck fuel in when the tank is low. This can go bad and the pump will still work fine when full, but begin to fail when the tank is low.

Also, be aware that the pump efficiency is greatly impacted by heat. Less fuel to pump means way more heat. I would guess teh t4r is return-less from the rail, but the fuel still gets heated (although less than on a full return). I've lost fuel pressure and almost blown up race motors because of heated fuel. In extreme conditions you need a cooler... Not applicable to the t4r motor or idle conditions... but it is more supporting data that it is not a great idea to run constantly on a really low tank.

 

[MONTYMTB]

Cmon [MENTION=91258]714runner[/MENTION] where else will you get cleverness like this?? and its free!

op2:

Free??? Every time [MENTION=66316]1engineer[/MENTION] gets clever with me, he sends me a bill!
:dammit:

 

[NorthWest 4R]

714runner Don't sweat it, as you can see most here already know this 5th gen section is filled with retired old couts with nothing better to do. You can easily identify this yuppy group as they regularly back up one another all jumping on the band wagon and like each others post's back and forth endlessly.

P.S. Most here cant even take what they dish out...

 

[jrandom]

714runner Don't sweat it, as you can see most here already know this 5th gen section is filled with retired old couts with nothing better to do. You can easily identify this yuppy group as they regularly back up one another all jumping on the band wagon and like each others post's back and forth endlessly.

P.S. Most here cant even take what they dish out...

LOL maybe true. Old coots or not, the fact is if we bothered to listen to people who have already made those mistakes and learned from them, then we shouldn't be making the same mistakes, right? We've all done it.

 

[714runner]

Yea, there are some people on this site that really don't know much of anything about cars, but like to bully people around because they have read things on the internet and have been here a while. LOL It's not that unusual for a site like this, but this seems much worse than most. I think most are just looking to have some fun.

Anyway, I don't really know the details of the 4Runner fuel system, but I have worked on many modern fuel systems trying to push them to the limits. There are many different things that could be at play. One thing is for sure, it has nothing to do with your exhaust or tires....

My first guess would be that you did damage the pump a bit and its overall efficiency has been decreased. What happens is that when the tank gets low the total head the pump must overcome is increased due to the increased suction head. It simply can't create enough pressure up at the fuel rail anymore and needs to be replaced.

Another guess would be that the sock/filter in your tank is clogged. They all get gunk in them, but you may have had a really dirty tank that again is creating more head pressure for the pump to overcome when low.

The calibration on the float could be off giving you a higher reading than reality, but that is not a common problem.

Finally, some systems have an inner canister that acts as a sump for the pump. They usually use a venturi effect from the return to suck fuel in when the tank is low. This can go bad and the pump will still work fine when full, but begin to fail when the tank is low.

Also, be aware that the pump efficiency is greatly impacted by heat. Less fuel to pump means way more heat. I would guess teh t4r is return-less from the rail, but the fuel still gets heated (although less than on a full return). I've lost fuel pressure and almost blown up race motors because of heated fuel. In extreme conditions you need a cooler... Not applicable to the t4r motor or idle conditions... but it is more supporting data that it is not a great idea to run constantly on a really low tank.

Thanks for really explaining how it works. I hope I didn't seriously damage anything, but I'm going to have it checked our next week and will have an idea of what to tell the mechanics thanks to you. As for driving on an empty tank, never again...
[MENTION=60421]North[/MENTION]West4R thanks pal

 

[JayceeP]

I think it's smart to know your tank. I've been on road trips with people who start getting uneasy at half of a tank and constantly insist we pull over to gas up. That's even more annoying.

Simple math (tank volume + distance travelled) will easily tell you what kind of range you have left. The computer consumption is a good baseline and then you can add a bit to be conservative. I usually add about 5% to the computer's consumption figure.

Aside from the mechanical reasons for not running the tank low, I also do it for geopolitical ones. Like what if supply gets cut off or people panic buy? I remember at the onset of the hurricane after Katrina we knew huge pump price increases were coming and all kinds of stations ran out of gas because everyone wanted to save a few bucks. Not a good situation if you're running on E. Given you live in an area prone to natural disasters (earth quakes) I'd probably keep my tank more full than not.

 

[phillyd2]

As for driving on an empty tank, never again...

It was not a pretty trip but we made without anybody dying. :wink2:

 

[mrtifftiff]

Aside from the mechanical reasons for not running the tank low, I also do it for geopolitical ones. Like what if supply gets cut off or people panic buy? I remember at the onset of the hurricane after Katrina we knew huge pump price increases were coming and all kinds of stations ran out of gas because everyone wanted to save a few bucks. Not a good situation if you're running on E. Given you live in an area prone to natural disasters (earth quakes) I'd probably keep my tank more full than not.

Are you serious? Is this the preppers rationale to keep your tank full?

In other news: the Yellowstone Caldera will one day erupt, ergo every person in North America should not let their fuel gauge dip below halfway. You know, just in case.

 

[Antman]

Oh, I get it.

April Fools Joke here.


Been there, done that.

 

[Titanpat57]

Oh, I get it.

April Fools Joke here.


Been there, done that.

The Town Drunk and Village Idiot weighs in, in one fell swoop....

This thread his reached completeness and come full circle...

 

[phillyd2]

Are you serious? Is this the preppers rationale to keep your tank full?.

Don't know if he is or not but we go by that rational. Not religiously but as a general rule we keep tanks about half and also keep extra fuel at home, not just for the tractors and atvs.

Our longest power outage was 11 days which means gas stations are closed too. Better to have and not need than to need and not have. :thumb3:

 

[Swarty]

Don't know if he is or not but we go by that rational. Not religiously but as a general rule we keep tanks about half and also keep extra fuel at home, not just for the tractors and atvs.



Our longest power outage was 11 days which means gas stations are closed too. Better to have and not need than to need and not have. :thumb3:

Was the natural gas out too? NG generators are cheap and any fast turn business like gas stations and fast food joints are crazy to not have one. One of my first jobs was at a station way out in the boonies of nm and we had a propane generator for power outages. It's just over 3k installed for an 11kw ng generator.

 

[JayceeP]

Are you serious? Is this the preppers rationale to keep your tank full?

In other news: the Yellowstone Caldera will one day erupt, ergo every person in North America should not let their fuel gauge dip below halfway. You know, just in case.

No need to get your tiffies in a jiffy.

The rationale is pretty straight forward. If it makes you feel any better, I don't go around hoarding gas, food, and ammunition, and filling up after every single outing. I just seldom let my tank go to empty... for what I would consider fairly logical reasons.

Our longest power outage was 11 days which means gas stations are closed too. Better to have and not need than to need and not have. :thumb3:

Exactly.

 

[phillyd2]

Was the natural gas out too? NG generators are cheap and any fast turn business like gas stations and fast food joints are crazy to not have one. One of my first jobs was at a station way out in the boonies of nm and we had a propane generator for power outages. It's just over 3k installed for an 11kw ng generator.

We have a whole house 20kw fed by 1500 gallons of propane. We sometimes feel a little bad about watching the big screen and surfing the net while popping popcorn in the microwave while the rest of the street is completely dark. Sometimes. :wink2:

 

[Stifler]

Vaginasezwhat?

 

[Ryan1975]

Cmon [MENTION=91258]714runner[/MENTION] where else will you get cleverness like this?? and its free!

op2:

 

[mrtifftiff]

No need to get your tiffies in a jiffy.

The rationale is pretty straight forward. If it makes you feel any better, I don't go around hoarding gas, food, and ammunition, and filling up after every single outing. I just seldom let my tank go to empty... for what I would consider fairly logical reasons.

Funny you mention that because I totally hoard ammo. :rofl:

Not for the obvious end of world scenarios but to protect myself against panic buyers. Every time there is a horrific shooting incident in this country, easily influenced drones are sent scrambling to buy up ammo and rifles because the govt. is going to ban them! I won't get caught out again the next time there is an ammo shortage. All I want to do is be able to go plink some cans!

What is it they say about those who live in glass houses? Haha

 

[3wbdriver]

Funny you mention that because I totally hoard ammo. :rofl:

Not for the obvious end of world scenarios but to protect myself against panic buyers. Every time there is a horrific shooting incident in this country, easily influenced drones are sent scrambling to buy up ammo and rifles because the govt. is going to ban them! I won't get caught out again the next time there is an ammo shortage. All I want to do is be able to go plink some cans!

^^^^THIS!!! I scored 200 rounds of .22 Magnum tonight! I haven't seen .22 Mag on the shelves since the Nov 2012 elections!!!!

When Hurricane Rita blew through in 2005 we had about 2 days of warning. I filled my truck up on the way home the day before she hit. We were without power in a 100 mile radius for the better part of a week. The wife and son hadn't put gas in their vehicles the day before. We had to siphon 5 gallons of racing gas out of my roundy round car to keep them running. I didn't have a problem. Guess who keeps their cars above 1/2 tank at all times during hurricane season now.

 

[FrontRange4Runner]

My simple suggestion would be to put $20 in the glove box and use it when ever you are below 1/8th of a tank. No wallet needed and it should ALWAYS be replaced when used - this can be transferred to other areas of life also.. Unfortunately if you have damaged your fuel system, you will be out an entire years worth of gas, or more, getting it fixed (could be worse...cough...TDI ) Fun fact: the helicopter I used to train on had a "low" fuel light that came on when there was approximately 2 min of fuel remaining.....not fun.

ALSO - The guys on here that are giving you a hard time are also the same people that would stop and be happy to help you out. They are not trying to chase you out of the forum, rather they just want you to learn form your mistakes. Feeling like an idiot and having people reaffirm that can be a very powerful motivator Go put $20 in your glove box (may also come in handy when the GF is needing any number of "woman" things).

 

[714runner]

My simple suggestion would be to put $20 in the glove box and use it when ever you are below 1/8th of a tank. No wallet needed and it should ALWAYS be replaced when used - this can be transferred to other areas of life also.. Unfortunately if you have damaged your fuel system, you will be out an entire years worth of gas, or more, getting it fixed (could be worse...cough...TDI ) Fun fact: the helicopter I used to train on had a "low" fuel light that came on when there was approximately 2 min of fuel remaining.....not fun.

ALSO - The guys on here that are giving you a hard time are also the same people that would stop and be happy to help you out. They are not trying to chase you out of the forum, rather they just want you to learn form your mistakes. Feeling like an idiot and having people reaffirm that can be a very powerful motivator Go put $20 in your glove box (may also come in handy when the GF is needing any number of "woman" things).

That is something I never thought about. I usually have some kind of emergency backup supply of something in my vehicle (blanket, first aid kit, work clothes, etc) why not have extra money?

Kind thanks for the suggestion, and I'll admit I did kind of asked for it, pretty stupid of me.