Most of my cars were ran with either the TQ3, TQ2 or the futaba magnum sport, THe TQ3 is a very good radio when it comes to entry level radio's, they can have a range of up to a quarter mile away with good batteries and a good antenna. Make sure you have the Tx crystal in the Transmitter, and the Rx crystal in the reciever, but mainly it sounds like a low battery warning, so change the batteries and see if that helps, if not check the crystals. BTW you must remember as well, that the further away the truck gets the more delay there will be in its reasponce. But on another note, I agree with thee above in upgradeing to a better radio, the Airtronics MX-3 is a very nice setup it is an FM computerized radio, that can be bought with/ or with out servo's, and can also be found for under $110.
Heres a picture of it.
And it can be picked up right here for $105 + shipping.
http://www2.towerhobbies.com/cgi-bin...I=LXCHA8**&P=0