Fuel Pump Relay question

[Chris Hall]

Turns out it was the Hall Sender.  I was wrong thinking that if the
signal from the sender disappears the tach "drops like a rock" to 0. 
It glides.

I put a new Hall Sender in, and the problem's gone.

I never knew / realized that the vacuum advance on the distributor
spun part of the hall sender assembly around.  Makes sense... easy way
to advance / retard the timing by moving the signal out of alignment
with the trigger wheel windows.

So, what I think was happening (since shaking the connector on the
OUTSIDE of the distributor...) was that the wires inside, although
they looked perfect, are actually broken (or at least one is) under
the insulation.  I realized that usually when the engine died, I was
either accelerating or letting the engine glide to idle approaching a
traffic light etc.  This broken wire theory makes sense, since the
VACUUM is changing at these points, and the hall sender is being
rotated by the vacuum, so the little wires inside the distributor are
getting moved when the sender rotates.

Thanks to everyone that told me "HALL SENDER" even when I was thinking
that my testing from the previous stalling issues I had done told me
the tach would drop to 0 when it was the sender.  Glad I re-tested
that theory...

On 6/8/05, Chris Hall <badcomrade at gmail.com> wrote:
> On 6/8/05, Huw Powell <audi at humanspeakers.com> wrote:
> >
> > >>Don't assume anything.  There must be fifty ways to get an engine to
> > >>backfire.
> > >
> > > Really?  I thought pretty much the only two reasons for a backfire
> > > were poor timing (ECU stopping and starting spark randomly falls under
> > > this) and too rich of a mixture.
> >
> > Well, without getting into a debate over this, aren't there fifty ways
> > that timing can be off, or the mixture too rich?
> 
> Oh, I'm not trying to debate anything.  Sorry if it seemed that way.
> I just don't know all that much about the cause of a backfire...
> 
> > >>I would say, test items to see what to replace, rather than randomly
> > >>trying to "think" of what it might be.
> > >
> > > I don't think in this case it's gonna be that simple.  The car runs
> > > 99% of the time, so whatever is causing the problem is WORKING (and
> > > going to test as so) 99% of the time also.  That's the biggest problem
> > > with this type of problem.
> >
> > Agreed - that's why I suggested things like a test light to tell what's
> > up at the fuel pump power wire.  Because it's such an intermittent
> > problem, it's going to be slow going diagnosing it.
> 
> I wanna catch this problem in the act so bad that I'm ready to go bust
> out that string of Christmas lights in my crawl space and build a
> "command center" out of cardboard and tinfoil to duct tape to my
> dashboard.  50 bulbs might just be enough lol
> 
> Oh how I wish my car's ECU had fault codes...
> 
> > >>By the way, methodically cleaning up all the electrical connections
> > >> under your hood might accidentally fix the problem.
> > >
> > > What should I try cleaning up other than the battery terminals (no
> > > corrosion on them at all), the battery ground wire (and all wires
> > > associated with it on the side of the battery tray...), and the ECU
> > > wires (they've been done in the last year), etc?  Am I forgetting
> > > something?
> 
> > All of them.  So what if you clean the washer pump or radiator fan
> > contacts, they'll probably like it anyway.  But there are all the sender
> > connectors, coil connections, etc.
> >
> > Good luck!
> 
> Maybe that'll get my rear washer pump going again.  Dunno -why- that
> stopped working.  Then again, my rear tail lights were so dim, I had
> to hook up a new ground wire to make them bright again... maybe the
> pump back there finally needs the same thing.
> 
> Stupid German wires!
> 
> Tomorrow (hopefully) should be another day of testing, etc.  I'll keep
> ya posted :)
> 
> Thanks Huw
> 
> > --
> > Huw Powell
> >
> > http://www.humanspeakers.com/audi
> >
> > http://www.humanthoughts.org/
> >
> 
> 
> --
> Chris Hall
> badcomrade at gmail.com
> "making girls cry since 1974"
> 


-- 
Chris Hall
badcomrade at gmail.com
"making girls cry since 1974"