I have a jr z1 with the pro spektrum module I am using all grey recievers, no the "pro models".I am only getting about 180-200 feet before I loose contact with the nitro powered car, the failsafe is not kicking in the car just rolls to a stop.I know the failsafe is programmed right because when i test it on the bench it works fine.The last time the car disconnected I left the radio on my tailgate and walked the 200 or so ft distance to get the car I noticed the failsafe not engauged,the green light on the reciever was on and solid both servos were also in thier neutral positions..no humming jittering no nothing.so i set the car back on the ground and walked back to the truck and there was no connection to the radio.I grabbed the car and brought it back to the truck and everything worked as it should, and it does untill the 200 foot mark or so.I have a dx3.0 aswell and when that radio was installed it never disconnected but at 300 or so feet the signal would get really really delayed.I would pull the trigger and about a half a second or so later the car would recieve the signal i sent it.I called horizon about it and they just gave me the"I dont know" and said to send in the radios, I find it hard to believe that 2 different modules in the jr radio and the 6 recievers i have all being defective..all the gear is brand new also.Im using a 1200 mah batt pack in one car and a 2000 mah pack in the other car at this point i have ruled out the batteries as a possibility.There is a really big race in like 2 days im going to and im hoping to fix this whatever it is before then any advice is appriciated.

Thanks for your help in advance.