Faulty Hall sender on 1988 240?

[jinglevo]

I'm trying to diagnose a no-start on a 1988 240, and I have tentatively narrowed the problem down to a faulty Hall sender. Just want to check if what I am observing is consistent with that:

--The engine cranks but does not start.
--It is getting fuel: The spark plugs are wet after cranking, and the fuel pumps and relay test out okay.
--The camshaft is turning when the engine is cranked.
--But it is not getting a spark when I crank the engine with a spare plug connected to the distributor or directly to the ignition coil. It does, however, spark when I jumper terminals B and C on the Hall sender connector. Power/ground to the ICU, coil power and resistance, and Hall sender power all check out okay.

Based on the above, is it conclusively a faulty Hall sender, or are there other possibilities I should consider?

Many thanks,
jinglevo

[lummert]

Have you tried swapping in a known good ignition module (power stage, ignition amplifier)?

[jinglevo]

No--I don't have one.

I was following the troubleshooting procedures in the Bentley service manual, which don't include extensive testing of the ICU. The jumpering of terminals B and C on the Hall sender connector is supposed to test the ICU "switching function," and if that gives a spark one is supposed to suspect the Hall sender. (If that does not give a spark, presumably the ICU is at fault.)

FWIW, I have tried swapping in another ECU, with no luck.