Does the cracked rubber hose which is part of the crank case ventilation explain what I get in throttle lag? I looked everywhere for a spare but I can’t find one. It’s on the left hand side of the manifold. I am planning to get the CPR6 when I get the cas

It could well effect the throttle. I would suggest looking at your local wreckers. Otherwise you car dealer parts supplier but I'd suggest it would be very expensive there.Or you could just replace with an off the shelf rubber hose, the hose that the current rubber piece joins to though will very likely require reworking.