Simply been looking and wanting a plugin to make first aid kits heal in 1 second but couldnt find any so just went and made one with the use of Crasher_3637 coding so credit goes to him and his following plugin which the code was taken from
https://forums.alliedmods.net/showthread.php?t=302822 No Friendly-Fire plugin.
So basically what this plugin does is sets the cvar first_aid_kit_use_duration to 1 pain_pills_health_value 99 first_aid_heal_percent 0.99 which means it heal ya to 99+hp and adrenaline_duration 60 adrenaline_health_buffer 45 cause i use a powerup plugin which lasts 60 secs so wanted the adrenaline speed boost to match its duration.
For anyone who just wants the first_aid_kit_use_duration change just only get the "Fast Healing KitDur only.smx"
NOTE:ONLY THE FAST HEALING KITDUR ONLY.SMX SHOULD WORK ON L4D SINCE IT DOESNT HAVE ADRENALINE TO USE THE FIRST ONE
To install simply download "Fast Healing.smx" and place the smx file into addons/sourcemod/plugins
or the "Fast Healing KitDur only.smx" if u desire the duration change only.