1991 Shadow fuel pump problem

1991 Shadow has a fuel pump problem. At first it
was thought the fuel pump was not working, but after
taking it out and testing it directly it worked. Any
thoughts as to what is likely to be broken (the tank
is not getting electricity)?


--
Jonathan Grobe Books
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On Thu, 20 Jan 2005, Jonathan Grobe wrote:

> 1991 Shadow has a fuel pump problem. At first it was thought the fuel
> pump was not working, but after taking it out and testing it directly it
> worked. Any thoughts as to what is likely to be broken (the tank is not
> getting electricity)?

The fuel pump receives power from the fuel pump relay, which in turn is
energized only on the Auto Shutdown (ASD) relay's say-so, which occurs
only when the Single Board Engine Controller (SBEC) gives the go-ahead,
which happens only if:
-The ignition is switched "on"
-The SBEC is receiving power
-The SBEC sees a pulse signal from the hall effect pickup in the
distributor.

Your first diagnostic step is to disconnect the negative battery cable for
two minutes, reconnect it, crank the engine, then check for stored flash
codes.

To check the computer codes:

With the engine off, switch the ignition key on-off-on-off-on,
leaving it "ON". Do not
go to "start", just "on" during this procedure.

Watch the "Check Engine" light. It will turn on, then go off, then will
begin to flash-out any trouble codes that have been stored. For instance,
if it flashes:

flash <pause> flash flash
<long pause>
flash flash flash <pause> flash flash flash flash flash
<long pause>
flash flash flash flash flash <pause> flash flash flash flash flash

Then you have a 12 (one flash followed by two) a 35 (three and five) and a
55 (five and five). 55 means "end of codes" or, if by itself, "No codes
stored. Check the codes and report what you find.

"12" means "start of codes" when observed via the dash light.
"55" means "end of codes".

If you get a code "11" (12-11-55), the hall effect pickup in your
distributor has gone and you'll need a replacement.

If you get no codes at all, your SBEC isn't getting power and you've
probably got a corroded wire or a blown fuselink upstream of the SBEC.

If you get other codes, other problems may be indicated (faulty ASD relay,
faulty fuel pump relay).

DS

Jonathan Grobe > wrote in
:

> 1991 Shadow has a fuel pump problem. At first it
> was thought the fuel pump was not working, but after
> taking it out and testing it directly it worked. Any
> thoughts as to what is likely to be broken (the tank
> is not getting electricity)?
>
>

Auto Fuel Shut-Off switch, located on my 94, behind an interior panel on
the drivers side near the rear wheel. Check your manual for location.
This must be manually re-set if tripped.



--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

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