Does a 1991 Ford E250 have o.b.d 1?
No, the 1991 Ford E250 did not have OBD-I. OBD-I didn't become mandatory in the US until the 1996 model year. 1991 vehicles, even those with onboard diagnostics, used a variety of proprietary systems that weren't standardized as OBD-I. You'll find a diagnostic connector, but it won't be the standardized OBD-I connector or protocol.