my chip used to play up after running the car for a while. i only had it in for about 50 miles as it just used to cut out and not start for a age. one thing i missed though. when i first bought it, i just plugged the fucker in after a clean up. it wasnt untill i done a head gasket that i thought whilst the battery was disconnected id plug the chip back in. guess what.?. this sorted the problem and it run 13 psi all day long and was reliable as death

worth a try?? who knows?