To eliminate the battery have it load tested. Most retail auto parts stores will do the test free of charge.

That said, I suspect the issue is low to no fuel pressure. If you turn the key on the pump will run and you can test fuel pressure at the schrader valve which is easily done with a fuel pressure tester also available at auto parts sellers.

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas