Have steering but no throttle after 30feet?

[gtxracer]

Hi guys,

I recently built a E-Revo, ditching all the nitro components. All the stuff from the nitro setup worked before I took it off. Now the electric version works but only until about 30ft or so. It's not the crystals or antennae since the steering will work no matter how far away I am. Here's my setup:

Mamba Max ESC - mounted by velcro
Starluck RC UBEC
Feigao 9XL
RCM heatsink and motor mount
94358 steering servo
5.5 connectors on the motor
4s Hyperion 4350mah LiPo
Deans connectors for the batt
enclosed Rx and BEC in Tekno Rx box
deanodized chassis (interference?)
Rx is mounted by velcro (stays put)

The antennae has been shortened but it hasn't had any effect on range in the past. I'm really stumped about this, I can't even get to full speed before I get out of range. The guy who had this setup before me said he used a Spektrum system, so maybe I just need to upgrade? Any ideas?