Can't help but think the problem is injector related, can you post the AMP/VOLTS waveform if you have it, for the #3 injector.

the pattern as in this capture,

[1997 Ford Windstar, Fuel Supply Waveform].[...]%2Fforums%2Fread%[...]%3Ff%3Dforum 2%26m%3D133714... Login to read more.

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