Looks as though the injector body wiring has been modified at some time (4 red crimp connectors) perhaps it used to go there. The loose connector only appears to have 3 pins though.
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Yes it does look a bit like a connector that would go to the EFI body - my Tipo 1.4 which is a similar engine and fuelling setup had a couple of these clipping on to the "carb" body.
Can you see where the other end of the wire goes? To me the sheathing around the three way wires looks like a sensor wire not part of the cars wiring loom.
Someone has modified the throttle body injector wiring in the background instead of theblack wire and 4 orange connectors It should be a single grey 4 way connector