Mine was one of the non adjustable Lindop Chip Kits, with the outboard posi and nega feed wires, but, like yours, started off totally silent and great performance improvement........then after the car had "learned" what the chip kit expected of it, the trouble started. My advice would be leave it at the setting you have found works with no adversities, and monitor over at least a month......hopefully the adjustability of your more recent Chip is the missing link. Mine is working away merrily in anurra T180.