Pump in Tank

Has everyone went to the fuel pump in tank and why?

 

Three reasons:

1. Electric pumps don't suck fuel very well, but do a good job pushing
it. If they were near the front of the vehicle, there would likely be a
difficult priming process if you ever ran out of gas.

2. The fuel in the tank helps keep the pump cool.

3. The tank acts as noise insulation, making the pump less annoying than
if it were mounted externally to the tank.

 

Less chance of vapor lock is one reason.

Matt

 

A fellow I work with never lets his tank get below 1/4 for that reason. He
figures the pump will stay cooler and last longer. Any thoughts on that?

 

4.......much more expensive to replace ! Is a shaft driven mechanical
pump obsolete ? Why ? They can't rob that much power, can they?

 

I recall replacing a few of those old mechancial pumps. Maybe I've been
lucky, but I've yet to replace an in tank electric.

 

I've heard lots of thoughts on this, but I've seen no data. I
personally believe this is an OWT (old wives tale). I believe the pump
is cooled by the gas it is pumping (most pumps are designed to have the
gas flow through the pump body), not the gas surrounding it. The
closest I've seen to data is from a person in another auto newsgroup who
claimed to have worked for a fuel pump company and he said this also.
The other reason I believe this is that I've never seen a single car
maker warn against running below 1/4 tank in any published document
(owner's manual, TSB, shop manual, etc.). If anyone has seen such,
please send me a reference.

The other reason is simple personal experience. I often run my cars
until the fuel is quite low, even occasionally until the low fuel
warning light illuminates. I've only had one fuel pump fail and that
was in a minivan with 150,000 miles on it. My Chevy truck has been run
low often, and even run out three times and it is still going strong
after 13 years and 95,000 miles.

It certainly doesn't hurt to refill before 1/4 tank if that makes you
feel better, but I personally think it is making extra fuel stops for no
good reason.


Matt

 

I usually fill more often in the winter. It just means I have a shorter
time to stand outside pumping the gas and freezing my ass off. The self
service savings myth has taken on quite a life over the years. In MA, some
towns do not allow self serve. The stations selling full serve are the same
price as the self serves down the street in the next town.

 

But it means you stand outside in the cold more often! I tend to fill
up more in the winter also, but the reason is that I like to have more
gas reserve in case I get stuck or something and have to spend the night
in the car.

Matt

 

You can always start the pump, then sit in the car while it fills the
tank. It the station is one of the stupid ones that removes the latches
from the pump handles, use your gas cap or one of the devices made for
holding the pump lever to keep the pump running while you sit in the
car. For that matter, you can make one really easily.

 

I agree that electric pumps are more reliable. I've replaced one in 30+
years of driving and I typically drive my cars over 150K miles. The one
I replaced was in a '79 Saab and it was a known problem with the pumps
they used.

 

Fuel injection pretty much eliminated that problem, though your point is
still valid.

 

I do that often even in good weather so I can clean the windshield or
whatever. Hard to find a pump with a latch these days but there is one I
station I use often. The Self Serve pumps also seem to pump slower than the
older ones too.

The one Shell station go use has a printed warning on the handle not to
leave the pump. The fear is static shock when you get out of the car in
winter and cause an arc. I always ground myself getting out anyway. .
This was interesting.
http://www.pei.org/static/

 

Those warnings are for real. Gas fires have happened because of the static
discharge upon leaving the vehicle to return the nozzle. First
recommendation is to not re-enter the vehicle until you're finished
pumping. Second recommendation is to be sure you're discharged prior to
returning to the nozzle area.

 

I haven't seen a fuel injector yet that takes fuel direction from the
tank and injects it into the engine. The fuel needs to get from the
tank to the point of injection so there is still lots of fuel line that
can vapor lock if not under pressure or with sufficent flow. Fuel
injection doesn't change much with respect to vapor lock.


Matt

 

Preventing fuel spills is also a big concern. If the automatic shut-off
fails, a lot of gas can be spilled by the time you realize it when you
are on the other side of the car washing windows.


Matt

 

And you can get hit by a car crossing the street so wear clean underwear.

Yes, it can happen. Have you ever been to a station on the Jersey Turnpike
or the like? Or in a busy city station? One attendant will often be
fueling three or four cars at a time. It is a scenario that happens
thousands of times a day all over the country. They depend on the automatic
shut-off to work. So do I.

 

A lot of dumb things get done in NJ. Just remember that in most states
you can and will be held liable for the clean-up costs. I hope you have
good insurance as that can get pricey.

Matt

 

Matt, for the past 45 years I've been driving, I've probably bought fuel
over 3000 times. During that time, I've seen tens of thousands of cars
filled either by self serve or attendants. Maybe I've just been lucky, but
I've never seen a spill from a defective pump shutoff. This sort of
activity has been going on all over the world, tens of thousands of time a
day. I suspect it has happened, but not enough that I'm going to change my
ways, nor will I worry about the cleanup costs. Just light a match and it
will be clean in seconds.

If you ever see me at the pump, just wave and move on because I'm not going
to grab the handle just to calm your fears. If they were a serious danger,
they would have been eliminated many years ago.

 

Actually, I think a better, and more accurate statement, would be that a
lot of dumb things get done in every state.

In my late teens and early twenties I was a petroleum distribution
engineer here in NJ. I worked at a very busy highway station (not on
the NJTP) and we would sometimes have eight cars going on one attendent,
with up to 24 cars fueling simultaneously. Not only did we NEVER have a
shutoff failure, I never even heard of that happening until you
mentioned it above. I would have to say that it is damn near
impossible. But I am sure it has probably happened somewhere. And
didn't someone get killed recently by falling debris from an airplane?
I would think that might be more likely than a spill from a failed fuel
cut-off.

Eric