5KTQ Maximum vacuum retard at 0.9 bar

[Paul Meyers]

The 87 5kcstqw goes to maximum retard (engine light comes on) at 0.9 bar.
While acceleration is acceptable, it's not what I'm used to with the other
two tq sedans. I have been unable to find a vacuum leak. When I test drove
the car (before I bought it) it registered maybe 1.3 bar. I have been unable
to duplicate that since. Now that the car has new paint, working AC,
functioning central locks, new shocks, rebuilt drive shaft, new Yokos, etc.,
I need to look at why the engine doesn't boost anymore. I completely
disassembled the intake system to check for leaks. Replaced the air and fuel
filters and Michelin man hose. All the vacuum lines seem to have been
reworked and don't show cracks. The turbo is spinning and there is no
abnormal oil use or smoke generation.

One point, I use regular gas. Before the flames, I also use regular in the
pearl 88 tq sedan and it boosts to 1.6 bar before the maximum retard light
comes on and displays really startling acceleration. What am I missing?

Paul Meyers 
Gray 87 5KCSTQ 1.8bar eurolights fuchs 145 kM, needs loom transplant 
Pearl 88 5KCSTQ 1.8bar eurolights fuchs bilsteins 125 kM 2pc-em k24 turbo 
Metallic White 87 5KTQW 191 kM daily driver 
Blue 86 5KCSTQ parts car