cars 87 turbo 2, lightly modded. running 9psi w/ fcd

So heres the issue, every now and then my car bucks in boost, problem came out of nowhere. one day was fine next day this started. somtimes it only happens once in a day, others multiple times in a row. boost does not drop but wont climb untill the jerk stops. it feels alot like fuel cutting, but its happend a 3-4psi on light throttle. happens in any gear, any psi, but always in boost.

TPS is tested good, FCD has alot of risistance (getting r-tec 1.7) I've rewired and upgraded fuel pump, no vaccum leaks,

I've had a simular issue when the positive wire on the alternator was messed up, I only spliced it from where it was good, so this could be the issue, I'll look into it.

How can I tell if my CAS is good?