Assuming the "weak spark" may be better than it appears, the fuel pumps should run (on '92-'93) with a jumper between the LEFT (input) sides of fuses 6 and 4. The pumps run immediately, when the +12v from 6 gets to the input of 4—which is where the Fuel Relay voltage is normally applied.

So connect the jumper, and if pump(s) can be heard, try starting and let us know if anything happens.

• In the meantime, here are some top of the head ramblings:

1) Can you hear the pumps for a second or two when the key is turned to ON (pos II)?

2) Did you check for broken t-belt? (While cranking, watch camshaft thru oil filler, or dist rotor. No movement = bad belt)

3) Try starting fluid/ether. Pull duct off throttle body, open throttle and squirt, and try starting. It won't run well duct off, but if it fires, there is some kind of spark available.

4) If NO SPARK, forget fuel issues because FI operation depends on signal pulses from the Ignition system.

5) Ignition, in turn, depends on pulses from RPM sensor reading flywheel position.

This picture shows the location of the RPM sender, but on an older 740, I believe.

Some better (240) pictures are shown in this thread.
Your '92 may have the original (yellow band) sensor, making it a prime suspect.

I don't believe the RPM sensor can be reliably tested with a meter, although resistance values are specified.

Keep us posted.


--
Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.