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-   -   Fuel Pump Timer? Pump Location? (http://www.autobanter.com/showthread.php?t=63546)

Nehmo April 26th 06 02:43 PM

Fuel Pump Timer? Pump Location?
 
I successfully changed the fuel pump on my 2001 Ford Ranger 3.0L 126"
wheelbase, flex-fuel truck [1]. But I have some unanswered questions,
and they'll plague me the rest of my life if they remain so.

Is there a fuel pump timer? How does it work, and where is it?

If indeed, the pump is cooled by fuel going *through* the pump, what's
the advantage of placing the pump *in* the tank?

How come Ford has different pumps for different wheelbase trucks that
are the same otherwise? How can the wheelbase, differing by a few
inches, have anything to do with the pump?

[1] The "flex-fuel", meaning can take either methanol+gasoline mix or
straight gas, part is indicated by the 8th character of the VIN, V for
flex-fuel, U for only straight gas. Apparently that detail is needed to
get the correct pump.
--
(||) Nehmo (||)


Telstar Electronics April 26th 06 06:51 PM

Fuel Pump Timer? Pump Location?
 
Here's my opinions:

Fuel pump timing... not sure what you mean by this. If your talking
about the time the fuel pump engages when you turn the key... with the
engine not running... then the answer is the computer is handling that.

I think the main reason for having the pump in the tank... cost.

As for different pumps for basically the same vehicle. The only reason
I could think of is that car manufacturers are always making revisions
to parts... attempting to improve them. The different pump in this case
may be an improved version of a previous pump. Remeber that the
improved version may or may not be backward compatible with previous
versions due to mounting bolts...etc. This is one of the major reasons
that application data is so vast at auto stores.

www.telstar-electronics.com


Nehmo April 26th 06 08:34 PM

Fuel Pump Timer? Pump Location?
 
"timer" not "timing". Actually I asked in a previous thread
http://snipurl.com/ppj3, but I didn't get an answer yet. If the engine
is dies, does the fuel pump stop after a period? If it does, how long
is this period, and does it begin again the next time the ignition
switch is put in the run position?
--
(||) Nehmo (||)


Telstar Electronics April 26th 06 09:42 PM

Fuel Pump Timer? Pump Location?
 
My answer is the same... when the engine is not running... the computer
is the device that runs the pump for a given time limit.

www.telstar-electronics.com

Nehmo wrote:
> "timer" not "timing". Actually I asked in a previous thread
> http://snipurl.com/ppj3, but I didn't get an answer yet. If the engine
> is dies, does the fuel pump stop after a period? If it does, how long
> is this period, and does it begin again the next time the ignition
> switch is put in the run position?
> --
> (||) Nehmo (||)



Mike Romain April 26th 06 10:24 PM

Fuel Pump Timer? Pump Location?
 
The pump need engine input to the computer that says the engine is
running, pump away. Otherwise it times out.

Turn your key from off to run and you will hear the pump start up. It
then will shut off. That is how long it takes the computer to time out.

As far as the rest goes, they wanted to make it very complicated and
difficult to replace the fuel pumps solely with the purpose to make the
mechanics that fix them money.

The old external electric and mechanical pumps were too easy for the
average joe to get, get at and fix.

Total planned obsolescence at it's finest.

The new pumps are cooled by the fuel coming back the return line going
into a jacket around them so they can make cheaper pumps and more
complicated seeming systems to 'snow job' the average consumer some
more.

The first generations of external pumps even had brushes you could
replace....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

Nehmo wrote:
>
> I successfully changed the fuel pump on my 2001 Ford Ranger 3.0L 126"
> wheelbase, flex-fuel truck [1]. But I have some unanswered questions,
> and they'll plague me the rest of my life if they remain so.
>
> Is there a fuel pump timer? How does it work, and where is it?
>
> If indeed, the pump is cooled by fuel going *through* the pump, what's
> the advantage of placing the pump *in* the tank?
>
> How come Ford has different pumps for different wheelbase trucks that
> are the same otherwise? How can the wheelbase, differing by a few
> inches, have anything to do with the pump?
>
> [1] The "flex-fuel", meaning can take either methanol+gasoline mix or
> straight gas, part is indicated by the 8th character of the VIN, V for
> flex-fuel, U for only straight gas. Apparently that detail is needed to
> get the correct pump.
> --
> (||) Nehmo (||)


[email protected] April 26th 06 11:09 PM

Fuel Pump Timer? Pump Location?
 

>
>Is there a fuel pump timer? How does it work, and where is it?


Fuel pumps are normally controlled through a relay and few seconds
'cycle' . With the key on, the pump is engaged. If no engine
movement (not running, sometimes no oil pressure, sometimes high
engine temp) is detected, the pump is disengaged in usually 2-3
seconds. This 'timer is part of the Engine Management System
(computer).
>
>If indeed, the pump is cooled by fuel going *through* the pump, what's
>the advantage of placing the pump *in* the tank?


The pump in the tank may be a cost saver or not. The advantage of a
submerged pump is it runs cooler and quieter with out suction leaks.
Replacing the pump may be less than an advantage.
>
>How come Ford has different pumps for different wheelbase trucks that
>are the same otherwise? How can the wheelbase, differing by a few
>inches, have anything to do with the pump?


Interesting question and I have no answer, except for possible fuel
types and fuel pressure requirements for different engines.
>
>[1] The "flex-fuel", meaning can take either methanol+gasoline mix or
>straight gas, part is indicated by the 8th character of the VIN, V for
>flex-fuel, U for only straight gas. Apparently that detail is needed to
>get the correct pump.
>--

It's interesting that Ford makes this distinction between gas and
alcohol fuels. It may mean that they are ahead of the pack with
different fuel pump seals/impellers/designs to accommodate the
emerging fuels. On the other hand why not supply all Fords with this
capability as a cost saver. Any difference in pump parts cost would
be more than made up in - less part numbers/ stockroom space, a
single production line, certainly less logistics in production and
distribution. This one is difficult to understand because Ford
traditionaly spends a nickel not a dime. Or maybe someone is
stringing you a line.

aarcuda69062 April 27th 06 02:05 AM

Fuel Pump Timer? Pump Location?
 
In article
.com>,
"Nehmo" > wrote:

> I successfully changed the fuel pump on my 2001 Ford Ranger 3.0L 126"
> wheelbase, flex-fuel truck [1]. But I have some unanswered questions,
> and they'll plague me the rest of my life if they remain so.
>
> Is there a fuel pump timer? How does it work, and where is it?


Yes.
A circuit in the PCM pulls the fuel pump rely control circuit to
ground, the PCM pulls the relay control circuit to ground if;
1) it senses the ignition circuit power up from off.
2) There is an RPM signal from the ICM.

> If indeed, the pump is cooled by fuel going *through* the pump, what's
> the advantage of placing the pump *in* the tank?


Fuel under pressure is less likely to vapor lock or foam.

> How come Ford has different pumps for different wheelbase trucks that
> are the same otherwise? How can the wheelbase, differing by a few
> inches, have anything to do with the pump?


The 126" pump uses a steel top flange, the 118" pump uses a
plastic top flange, there are also differences in the plumbing.
Apparently there is a marked difference in the design of the fuel
tank/system between the two wheelbases.

> [1] The "flex-fuel", meaning can take either methanol+gasoline mix or
> straight gas, part is indicated by the 8th character of the VIN, V for
> flex-fuel, U for only straight gas. Apparently that detail is needed to
> get the correct pump.


Indeed, the flex fuel pump would need certain material upgrades
if it is to survive the higher alcohol blend.

[email protected] April 27th 06 02:22 AM

Fuel Pump Timer? Pump Location?
 
aside question,

not to interrupt the poster's original question, but I had to have a
fuel pump installed on a '93 6 cyl. 3.3 chrysler t-c minivan - twice.
600 bucks a pop.

and, another engine same kind, same year model, has never had any fuel
pump problems - why? just curious.

what can cause an electric fuel pump in the gas tank to fail?

mho
vƒe

>double dog dare you, sound familiar?


>to reduce your driving by *-**10%.



Nehmo April 27th 06 05:45 AM

Fuel Pump Timer? Pump Location?
 
Well, thanks. That settles it.

--
(||) Nehmo (||)


Kevin April 27th 06 09:52 AM

Fuel Pump Timer? Pump Location?
 

"Nehmo" > wrote in message
oups.com...
> I successfully changed the fuel pump on my 2001 Ford Ranger 3.0L 126"
> wheelbase, flex-fuel truck [1]. But I have some unanswered questions,
> and they'll plague me the rest of my life if they remain so.
>
> Is there a fuel pump timer? How does it work, and where is it?


The ECM (engine control Module) has circuitry that provides the ground for
the fuel pump relay. That circuitry contains a timer circuit that only lets
the pump run for a couple of seconds if there is no rpm signal recieved from
the engine.

>
> If indeed, the pump is cooled by fuel going *through* the pump, what's
> the advantage of placing the pump *in* the tank?


Less expensive to make a pump that does not need to provide lift ( suction
to pull gas from the tank).

>
> How come Ford has different pumps for different wheelbase trucks that
> are the same otherwise? How can the wheelbase, differing by a few
> inches, have anything to do with the pump?


Fuel tank configuration is different on different wheel bases. Therefore
pump design varies.


>
> [1] The "flex-fuel", meaning can take either methanol+gasoline mix or
> straight gas, part is indicated by the 8th character of the VIN, V for
> flex-fuel, U for only straight gas. Apparently that detail is needed to
> get the correct pump.


Different pump construction materials are needed to handle the corrosive
properties of extra methanol


--
Kevin Mouton
Automotive Technology Instructor
"If women don't find you handsome, they should at least find you handy"
Red Green
> --
> (||) Nehmo (||)
>





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