'91 200q not reaching full boost

[C1J1Miller@aol.com]

Can't seem to get to full boost (1.8) in my '91 200q (20v).  The boost guage
(in the 
computer) only reads 1.6, or occasionally 1.7.

The hose running around the back of the engine (crankcase breather hose?) is
soft; could this be causing the problem?  It doesn't seem to be cracked, just
"squishy".

I've been running high test gas (would this affect boost or just timing??); I
cleaned the air filter (but haven't replaced it yet, it is due!); checked
hoses etc. for signs of cracking or air leaks.

Plugs are bosche platinum; haven't been changed in a while, but look good.
 The compression for the engine was just checked (pre-purchase) and was 160
for each, except one at 163.  I don't yet have the Bently, so I'm running in
the dark!

Also, when starting the car, it cranks for several seconds longer than
expected before starting, and surges up and down one mark on the tachometer;
is this normal?  The car has 70k miles, original oxygen sensor.

Thanks in advance; Chris Miller, Windham NH  c1j1miller@aol.com
Also, I'm selling my old Bently for the 4000 (as well as still selling my '86
4000csq)