Idling problems with my TR15 buggy

Heya guys, I was wondering if anyone could help me, this is really got me baffled.
My new buggy has been properly ran in and now I am running on 15% nitro. But it seems to not idle for very long. I've set the idle screw so the wheels bearly start spinning when I take it off the ground, but after a few mins of driving around, if I pull it up to check something or if the failsafe kicks in when it's far away, she will idle for a few seconds then die.
I raised the idle screw up a bit so the wheels would spin a bit more, but when it comes to a stop, the idle will rise then fall, then it stalls! :banghead: :banghead: :banghead:
There is no low speed needle on this carb. So I am stumped.
Please help
P.S I have also changed the glow plug.
Cheers guys

Hmm.. Check the air mixture screw.. and check the throttle trim on the controller.. If it dies after a little while of driving, try running it with 10% nitro...