floods at idle on 1994 Ford F-350

will not power up scanner. floods at idle. back fires. run roughs.

Asked by for the 1994 Ford F-350
Check for power and ground at the OBD2 connector
Check that pins at the connector are fully seated in the OBD2 socket. Once the scan tool can communicate with the computer in your car it wil likely show the area the problem is related to.