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Disconnecting the AMM immediately forces the ECU into "limp home mode", which operates the engine under pre-programmed conditions for fuel mix and timing advance, ignoring a number of input sensor signals. The engine will run a bit rough at idle, will be hesitant on acceleration, run with less power at moderate rpms, and act like it's governed at anything much above 2,600 rpm.
AMM air flow sensing is the main input signal ignored. If the engine now starts and runs, albeit roughly and hesitantly, then a faulty AMM goes to the top of the suspect list, by far.
One thing you can try is using spray contact cleaner to thoroughy clean both ends of the AMM connector. Also when connected, peel back the rubber boot and making sure the wires are pushed in. The female contacts are supposed to be packed with dieletric silicone grease (spark plug lubricant), also with a wipe around inside the lip of the rubber boot, for moisture and corrosion protection. Certainly worth a try as you could have a marginal connection, although I somehow doubt it if your sympoms are as consistent as you indicate.
Off the top of my head, the only other input signals that might be forced as ignored in limp home mode are the ECT and O2 sensor. Neither is critical for engine starting and initial operation. OBD diagnostic codes pointing to faults such as fuel trim and the O2 sensor can often be red herrings after a no start, rough running, stalling situation. A failed ECT often results in a poor base idle before it starts affecting engine response. A failed O2 sensor by itself usually just affects fuel trim (rich/lean), not starting.
You could try spending time trying to diagnose, test, and confirm if the ECT and O2 sensor are healthy (which they may or may not be), but IMO, the fastest way to get on top of diagnosing your no-start is likely to swap in a known good AMM, reset the OBD diagnostic codes and take it from there. Can you beg/borrow one for a test? Your '94 B230FT is LH 2.4. Any Bosch AMM with the -016 part suffix will work from an '89-'95 940/740/240. It never hurts to have a spare anyway. Used is okay, especially for a spare.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
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