I think you may mis-understand the function of the cam follower. Unless it's failed, and you ought to know that for sure, then it is unlikely to help your problem. I'm not saying don't change it but I'm trying to say don't expect changing it to help you.
I agree stu, reason is, that the fuel is still supplying high fuel pressure on occasion, meaning the pump is mechanically driven, and that one minute its supplying enough, and another minute it isnt. Kind of points either to mapping requesting too much for a standard pump, or i could have a fuel delivery issue, possible fuel blockage , I still dont believe my stock pump is worn out. As not long ago on jkm's rollers, the car has always performed VERY well on a stage 1 map.
Fuel filter has never been changed, so might give me a clue.
Im doing some logs tonight, so will list the results later.