Help!

[magman]

Ok...I have a mrx-3 that I converted to BL using a 1512 1800kv on 6s running a spektrum set up and I have an issue. The car hesitated badly upon startup and then after a few seconds rockets away. Now, sometimes it will just barely crawl on the floor...take it off of the floor and put it on my stand and the throttle response is crisp and it seems to act as it should. I have fiddled w/the spek rx for an hour, rebinded rx, redid esc bind, etc...with no luck.

I charged the batts fully a week ago so they should be good

any ideas? I just checked all my solder joints and they seem all good