Propulsion

this has happend to me a couple of times, too lazy to fill up on time, and overestimating my fuel efficent civic, and paid for it. I was wondering if this is bad for the engine or not? Wouldnt it be running lean before it dies?

Spade

Yeah it is bad. You are draining your fuel system and your fuel pump is pumping air......not good. Injectors dry out....not good. Your fuel pump pick up is sucking all the sedement off of the bottom of the tank into the fuel pump/lines/filter/fuel rail/and injectors.....not good.

Start filling up earlier.

RyanR

Sedement? Since when is sedment on the bottom of a fuel tank? When I swaped out my fuel pump the bottom of the tank looked fine, no dirt or sedement at all. How would sedement be getting into the gas? Gas tanks are all non-corrosive. Same goes for the tanks that gas stations use and the trucks that haul the gas around.

Spade

Then there would be no need for a fuel filter huh?

Even open your gas cap and not immediatly place the fuel nozzle in....or ever check to make sure the fuel nozzle is clean before you insert it.
What do you put your fuel cap on while you have it off of the car to keep dirt from getting on it????

Want more?

RyanR

Have you ever looked in your fuel tank?

Daemione

I hear this all the time, and it makes zero sense. The fuel pump pickup is at the bottom of the tank anyway.


[Modified by Daemione, 3:56 PM 7/5/2002]

Spade

You know, we can argue this all you guys want. **** gets in the tank, it either float or spreads around the gas tank.

If you have 10 gallons of fuel and 100 particles it is hard to suck up those particles.

When you have 1 gallon of fuel and 100 particles, it gets a hell of alot easier to suck that **** up.

WHEN YOU DRAIN THE TANK YOU SUCK EVERY GOD DAMN THING UP. Just because you cannot see it does not mean it isn't there.

TurboSedan

For all but Spade!

B19CivicHB

GO SPADE!!! GO SPADE!!!

-Nick-

PS: He's right fellas...

BigMoose

Everyone else explained the sediment issue. Now for the fuel or lack thereof issue.

When you run the engine out of fuel, does your mixture go rich or lean? See the problem?

Deliberately making your engine experience a lean out is not prudent in my book. If it happens idleing that is one thing, under load with a potential detonation event is another.

Another reason to keep a tank near full is cooling of the electric in tank fuel pump. Some high volume, high pressure pumps are rejecting over 100 watts of heat into the gas in the tank. The less gas the less cooling for the pump.

Regards,
BigMoose

Mikey3000

Spade knows what he's talking about. He wins the argument.

Daemione

Please pay attention to what I'm saying, and what I'm not saying. I'm not saying there isn't foreign material in the fuel tank. And I'm not saying it is good to run out of fuel all the time.

What I am saying, is that your original statement:
makes no sense, since the pickup for the fuel pump is at the bottom of the tank.

Any foreign matter that gets into your fuel tank will eventually get sucked through the fuel pump (unless you somehow manage to get a really buoyant floaty in there). Imagine a 15 gallon fishtank in your backseat, and drop a couple of peanuts in it. Through the course of a week or two, with all the cornering, braking, & accelerating that is involved with daily driving, that crap is going to make contact with every part the tank there is. Being sucked into the fuel system is inevitable.

Running out of gas will probably accelerate the process of this, but like Spade said, there is a reason you have a fuel filter. The danger in running out of fuel does not lie in foreign material clogging your fuel system.

As far as a fuel pump attempting to suck up air instead of fuel, I'm not familiar enough with how fuel pumps work to know whether this would reduce their lifespan. But you will not lean out & detonate at the bottom of the tank, as it all ECU controlled & ignition will be retarded rapidly to provide knock. The engine will not continue to run if it is too lean to do so safely - that's why you stall.

BreakStuff

actually the fuel pump pump pick-up rest approx 1/4" from the bottom of the tank, it will suck up sediment when the fuel level is lower, the fuel filter does a good job but will NOT filter out all sediment..The mid 80's Hondas incorporated 2 seperate filters but till this day we still have to clean the dirt/rust sediment from the carb's.. Its not only an issue of "sediment" but also amounts of water that have accumulated in your fuel tank.. water is heavier than petrol and will rest on the bottom of your tank, no fuel filter seperates H2O from gasoline..

matt_sb2000

Really funny that you would call me a moron in another post, and then this.

Yes, obviously the car will go lean. Not enough fuel = lean ... It doesn't just run out of fuel. The pump will supply some air and fuel togather at first... Pump not made to compress air... fuel pressure low... detonation imminatnt (sp?)...

Matt

YeuEmMaiMai

if you routinely run your tank dry you will most likely burn up a fuel pump since they rely on the gas to keep them cool. I will not let my car ever go below 1/4 tank and I fill up usually around 1/2 tank

YeuEmMaiMai

while it may be possible to suck up fine particles. it would be extremely difficult to suck up anything large since there is a nylon "sock" on the fuel inlet to the pump that does 2 things

1. seperate the water from the fuel gas
2. blocks larger crap from getting to the fuel pump

I agree with you 100% you don't want crap in your fuel tank and the best way to avoid it is to keep the tank full

RyanR

I guess no one on this board wrenches on their own car. Next time your having your "mechanic" install a fuel pump, shine a light in the tank and look at the bottom. If you have a visable amount of dirt, then you have other things to worry about. Unless you go off roading with your gas cap off, I don't see how you can get dirt in there.

BigMoose

I believe Matt's statement needs clarification for the community. I thank him for refreshing my memory thru the IM function.

The topic of that series of posts was using PVC plastic pipe for compressed air systems. My comment was something like: Only an idiot would use PVC for compressed air systems..... I then went on to recommend that they use copper tubing for the air system as I have done in my shop. The reasons being that PVC will shatter and propel shrapnel when it fails....ie it is not fracture tough... and Copper will only split. Also the thermal advantages of copper will condense the moisture."

I stand by my statement that only an idiot would use PVC for compressed air systems.

Substantiation here: http://www.lni.wa.gov/wisha/hazalerts/902.htm

Partial quote of url: "PVC pipe not to be used in compressed air systems
The Department of Labor and Industries warned consumers and employers in May 1988 that plastic-polyvinyl- chloride (PVC) pipe cannot be used in compressed air piping systems without risk of explosion. ............."It is recognized that while adequacy of strength is an important element in the safety of a compressed gas piping system, consideration must also be given to the nature of failure should accidental failure occur, whatever its cause. Above-ground piping which fails by shattering can present a serious hazard to personnel by the resultant flying shards, or pipe fragments, which are rapidly propelled by the released energy of the suddenly decompressing gas. .........NOTICE TO EMPLOYEES: If you suspect that a pressurized PVC piping hazard exists, bring it to the attention on your employer. If you do not obtain satisfactory results, you may file a confidential complaint with the Department of Labor and Industries. Complaints are investigated promptly. Call the Department's toll free number at 1-800-423-7233."

Do Not Work Near an PVC Air System...even at work.


I told matt I will pull the references for him. Done, see the above insertion

Regards,
BigMoose

edit to provide web site and technical substantiation that PVC shatters in failure.



[Modified by BigMoose, 10:48 PM 7/6/2002]

E Swift

97CivicFerio, that just made my day seeing that picture. LMAO!

TurboSedan

I had to use it, I get a good laugh every time I look at it!

SuperTwinz

so what spade is saying is that if you have sedement in your gas tank you are assed out and the fuel filter doesnt work anymore. so get a new motor.

DUFFY

running out of gas is a good thing. try to do it more often

JMF

The worst thing about running out of gas is getting laughed at by everyone driving by

Is that a good enough reason to keep your tank full?

areyouasian

found this on a website provide by the city of Boston:

http://www.cityofboston.gov/isd/weig...s/gasoline.asp

quote from site:

Also, avoid purchasing gasoline when you see a “gasoline storage tanker” delivering gasoline to the station. When the high volume of product empties into the underground storage tank it can “stir up” sediments located at the bottom of the tank. If the station has a poor filter, this sediment will end up in your tank, clogging your gasoline filter.

just wanted to clear things up. also i remember either superstreet or SCC had articles in their mag a while back saying the same thing. dont know how true it is but if its on a government site i dont think they would be BS-ing it without checking it out first.

virginia_dude

I can guarantee you MOST gas tanks aren't made of non corrosive materials, most are just plain mild steel and they do rust. THere are a few plastic tanks and Stainless tanks out there I am sure but the lions share CAN and DO rust.