In a message dated 9/30/04 8:55:20 AM, felder@KNOLOGY.NET writes:

<< 1. Bad ground between the head and the chassis. Test: run a new ground.

2. Bad hall-effect sender. Test: ??

3. Bad cold-solder joints in the computer. Test: ??

4. Coil. Test: I assume he can test by pulling the coil wire and
checking for spark to ground when the engine is hot.
 >>

Here's a better itinerary:

1.  Test for spark by pulling the high tension coil wire from the distributor
and connecting it to a grounded spark plug.  Then you will know if it truly
is an ignition problem, although it will not isolate the cause.

2.  No spark - Check for primary voltage at coil - Check the DC resistance of
the primary and the secondary.  Anything suspicious here begs for the
substitution of a known good coil.

3. Check the power supply at the Hall sender.  Connect a logic probe to the
Hall sender.

4.  As far as checking the computer for cold joints, a discerning eye behind
a good magnifying lens should be enough.  David Beierl has reported here that
he has resurrected more than one queefed out piece of electronica simply by
reflowing all of the solder joints.  But, he knows what he is doing and, I would
think, he doesn't do it with a Wen 450 soldering gun.  If you are not
familiar with this type of work, it would be best to find someone with a temperature
controlled soldering iron to do it for you.

George