5kcsq low boost-help?

[Jon Archibald]

Hello All,
We've recently added an '86 5kcsq to the family stable. Car has full records
and runs smoothly and quietly, except for low boost readings. With my 5k
experience limited to my NA 2.3 5ksq, I cannot determine by seat-of the
pants testing how weak the car feels, other than the fact it does not feel
noticeably more powerful than the NA car. Boost reads between 0.0 and 0.3
bar at idle, and maxes out at 1.0 bar 95% of the time, occasionaly bumping
to 1.1. Reading through the paperwork, there is a note from a mechanic that
the auxiliary water pump is disconnected. I'm wondering if the problem is
due to an under-cooled oil-coked turbo which does not spin freely, due to
the engine being in "limp home" mode because of a faulty sensor, or if
perhaps the boost readout is somehow wrong. Any BTDT or ways to rule out
culprits here?
TIA,
Jon Archibald
'85 urq
'86 5kcsq
'87 5ksq