In a message dated 12/27/00 10:14:32 PM Pacific Standard Time,
[EMAIL PROTECTED] writes:
> Ok next
> >question have you checked to see if there is any gasoline coming out of the
> >fuel pump? Did you disconect the fuel line (at the fuel filter) and try to
> >turn over the engine (a friend, turns the ing. key on as in your trying to
> >start the car) while you watched to see if gasoline was squirting into some
> >kind of a contaner ...
>
> You can also check the pump by listening for it. It's right under the back
> seat and turns on with the ignition before the car starts (in run or acc,
> don't remember). If the pump has completely failed, it will be silent.
>
>
>
Stede:
Good point you brought up, about listening for the fuel pump to come on when
the ignition is turned on and I think it only comes on in the start/run
postion. But even if the fuel pump does put out some gasoline with the
ignition switch turned to what ever postion it takes to start it pumping
fuel, if the pressure is not high enough the engine will/might run at idel
because there isn't a load on it, but if the fuel needs of the engine are
greater than what the fuel pump is able to supply when the engine RPM's
become higher it will be starving for fuel. Because the Sentras are fuel
injected engines it even more important to check the fuel pressure with a
guage to make sure that enough gasoline and fuel pressure is getting to the
injectors. Carburetor powered cars/trucks without to many mods or stockers
can get away with out as high a fuel line pressure partly because the
carburetors have what are called fuel bowls build onto/into the carburetors
which hold a small amount of gasoline and this is pumped into the carb when
needed, Holly carburetors and older style ones called stromburg 97's are good
examples of carbs with fuel bowls but they also require fuel floats to make
sure the fuel level is at the right height with in the fuel bowl, they work
along the same way as the water level inside your toilets water tank, LOL (no
flames, PLEASE) I just put than in there incase you haven't ever seen the
inside of a carburetor so you'd have a better idea how they worked. If I
remember right most stock powered cars with carburetor powered engines with
out any mods run around 9 to 15 pounds of fuel line pressure and the fuel
pumps are located on the engine block its self and are powered off of a lobe
from the engines cam shaft. On Sentras (I think older Sentras around1982 ( I
could be wrong) had a fuel pump located on the engine block also, facing the
firewall) and other newer cars/trucks the fuel pump and fuel pick up is
located right in the gas tank and the fuel pumps are what are sometimes
called "pusher" type fuel pumps because the fuel is pushed from the fuel tank
up to the injectors and not sucked up into the fuel line like ones mounted on
an engine block. You also have all the fuel/vapor recoverly lines going back
to the fuel tank because of fuel/smog emissions reasons. I don't have a
factory service manuel handy or I'd look this up but I think the fuel line
pressure for newer fuel injected Sentras is around 38 psi, I maybe wrong
about the fuel line pressure so it would be best to check this out first.
Stede, I know this wasn't your question and you are only helping out so I
hope I didn't bore you to death with this long post. LOL
Ron
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