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If I'm reading my '89 green book correctly, Bruce, for a B230F LH2.4 system, you can do as you say, but you also need to restore fuse 1 functionality with a jumper wire and ideally you'd want fuse 11 jumpered as well. Battery power looks like it's on the back terminal of fuse 1 (not the front as you indicated) while the front terminal provides power for the injection system (the ECU and indirectly the AMM and IAC valve). For fuse 11, the back terminal can be used to directly power the main fuel pump as you indicated. The front terminal of fuse 11 feeds the in-tank pump and O2 sensor heater. I'd also try jumpering only to the back or front terminal of fuse 11 to see how attempting to run on only one pump changes the symptoms.
An alternative is to slide out the relay tray, remove the injection system relay (fuel pump relay, middle row, leftmost) and in the relay socket jumper together pin 3 (terminal 30), pin 5 (87/2) and pin 1 (87/1). Note that pin 3 is always hot (battery voltage). I'd probably use paper clips to jumper at the relay socket as there is a fair power draw. Do visually check the f/p relay socket for signs of overheating -if the plastic melts, the terminal connector may push out which makes for poor or no contact. Unfortunately you can't use jumpers at the relay socket to operate just the main or in-tank pump -that's best done at the fuse panel.
I sure agree that's a good test to try. Too bad proper fuel pressure testing can't be done to totally rule out fuel delivery problems. Operation of the main fuel pump is certainly suspect. You can't ignore the fact that '89 ECU's are certainly famous for providing poor f/p relay ground and 30 seconds may be just enough to overheat a faulty transistor.
Another thought, if the main fuel pump was out, the in-tank pump alone should start and run the engine, but if it was in the process of failing it might run for less than 30 seconds before seizing. That in-tank pump behaviour I've seen when playing with a "dead" one. I certainly agree with others that a bad AMM can cause a stall after starting, but in my experience it's more like a stall immediately after catching, not 30 seconds of running.
Given all that's been swapped/replaced on this car, my next prime suspect would be the rpm sensor. I don't think they usually fail with such consistent symptoms, but the original '89 sensors were certainly known weak spots for stalls and no-starts.
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Dave -own 940's, prev 740/240/140/120's & quasi-expert only on a good day
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