ok i have been trying to figure out why i cant get my trouble code system to work on my 94 z28 setup. i have installed all wiring motor and trans out of a 94 z in my 70 chevelle. ive had this setup for two years now but have never been able to get the diagnostics port to work. when i jump it it does nothing. anybody have any ideas? i hate to not know whats going on with this. please help.