So thanks to a number of people, but especially Ward Smith, I've managed
to track down the problem to electrical.  Nothing is coming off the
coil, despite having proper voltage.  I actually had a spare coil handy
and swapped it in with no change.  Oh, yeah, this is fun...

Following Bentley, I tested the Hall Sender(28.43) and got ~11V, so that
looked good.  However, on the function check, I didn't get any flicker
from my light meter.  Uh, Bingo?  Since I was at the second to last page
in the chapter and since the most complex ignition system I've worked on
prior to this was in a '76 Bronco(battery, coil, distributor, wires,
plugs and voltage regulator: now that's what I call an ignition
system!), I decided to do the final ignition switching function
test(28.44) and it returned 4.66V, which seems normal.

So, can I take Bentley as definitive: dead Hall sender?  If not, I
assume the Hall control and Hall generator is next, but is it the same
process to test as in the Digijet section of Bentley

Thanks much,
-MB

Mark Belanger wrote:
> Greetings all,
>
> After scouring Gerry and trying to digest about a million messages with
> the topic of "won't start," pouring through Haynes and Bentley, I'm at a
> loss.
>
> Here's the scenario:
> I have a '91 Automatic, originally from Florida that I picked up about 6
> months ago in California.  She's always purred(apart from a month of
> cold stalls, but that went away).  About a week ago, I was driving back
> from work had gone about 5 blocks when she just died at a light and
> wouldn't start.  Plenty of juice and the starter cranked, but she
> wouldn't catch.  It was raining early that day, so I chalked it up to
> some electrical problem, but after a week in a dry garage, she's still
> dead.
>
> Here are the things checked and/or replaced:
> - Fuel: half a tank
> - Battery: removed and fully charged
> - Battery contacts cleaned and greased
> - New cap, rotors, wires
> - New plugs - old ones looked very clean
> - Checked coil resistance per Bentley
> - Checked voltage coming off Hall wiring connector per Bentley
> - Checked air flow meter resistance per Haynes
> - Checked fuel relay on ignition - clicks
> - Checked fuel pump on ignition - pressurizes
> - Checked and cleaned two ground bolts near coil
> - Checked every visible connector within the engine - no corrosion
>
> Odd things:
> - rotor and inside of cap *heavily* scored at contact points.
>  - Figured it hadn't been replaced in a while.
> - Power steering pressure sensor disconnected.
>  - However, it was covered in grease, so it had been disconnected for a
>    long time.
> - Wiring harness at tee near left rear lights, split with some cuts.
>  - Suggested the previous owner had some electrical problems that were
>    troubleshot.
>
> So none of this points to a clear culprit to me.  The only remaining
> tests on the ignition system listed in Bentley that I haven't done
> involve the ECU, which I'm not comfortable screwing with yet.  Also,
> having never owned a fuel injected car before(god bless the carburetor),
> I've resisted anything beyond superficial fuel system tests.
>
> Is anyone aware of a thorough checklist of how to troubleshoot such a
> problem.  I'd really like to be able to track this down myself, but am
> at a loss to what to do next.
>
>
> Thanks,
> MB