Audi A4 B5 1.8t Lack Of Power

[hybridavant]

Hi everyone i know this is not an S2 but maybe someone here can help as its VAG?.
The story goes bought a p reg 1996 A4 avant last year with engine trouble , its the AEB 1.8t 150bhp.
Problem with the engine was hydraulic cam chain tensioner was shot ,this caused the oil pickup to be partially blocked with nylon from the tensioner blade,ending with one of the camshaft caps completley worn away .
Replaced cylinder head and renewed cam chain tensioner.
Removed sump and cleaned pickup , checked bottom end ,all ok.
Engine starts and runs perfect ,just has lack of power .
Boost preasure is only 7psi on this engine , the most i can register on boost gauge is 4.5 to 5 psi!.
I have replaced the Diverter valve,preasure tested the turbo system , all ok .
Checked the cat for & exhaust for blockage ,all ok.
Replaced air mass meter.
Checked the fault memory no errors .
Swapped the N75 for a known good unit .
Removed turbo and checked ,all ok.
Previous owner had wastegate actuator replaced , i checked the adjustment ,all ok.
Swapped turbo for known good unit .
All of this has had little affect , only air leak found was diverter valve.
So if there are any diagnostic guru's out there pls let me know what you think!!.
P.s have access to snap on scanner if data needed.
Thanks in advance

[hiltoa]

Sounds like you've checked most of the things I'd suggest - Have you got access to VAG-Com? This may show up something.

Otherwise, it may be worth posing the question on www.audi-sport.net - they're a pretty helpful and knowledgable bunch on there (if not quite as fanatical as this lot... ).

Hope you get it sorted.

[GT500]

Check the valve lift, cam worn?
" " cam timing.
cat fooked.