If you remove fuse #4 when you do your test, it might help you isolate this. With the ignition off and fuse 4 out, apply 12 volts to the left terminal of fuse position 4. This drives the main pump only - listen under the car. Then apply 12 volts to the right terminal of fuse 4. This drives the tank pump only - listen at the gas filler tube with the cap off.

If you have an ammeter that will handle 10 amps, you can also check current draw with the meter for each of the above tests, instead of just jumpering with a wire. As per Bentley, the main pump should draw no more than 6.5 amps, and the tank pump should draw 3-4 amps.


Re: the gray plug. If you really want to resolve your mechanic's questionable diagnosis, you could first try a test yourself by separating the connector and seeing if it still starts. (If I understand correctly, you're saying it's starting fine now, right?) If you do this test, don't run it long this way, as the alternator won't be charging. Presuming it starts fine this way, you can decide to:
A) get another mechanic (maybe the best choice)
B) go back to your mechanic, show him the test, and ask him to explain how his tech concluded that it was an injector issue

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David Armstrong - '86 240(350k km?), '93 940T(270k km), '89 240(parts source for others) near Toronto