Machine is right... It's really quite obvious if you just search for anything EMP related in Firestrm.ini (which seems like the most logical thing to do when you're having trouble getting the mobile EMP to work in TS)...
QUOTE
; Hack to make MultiMissile & MobileEMPulseWeapon work! Don't change data!
[WEEDGUY]
Secondary=DualRockets
Elite=MobileEMPulseWeapon