Audi a6 1998 2.5 tdi power loss

[kevsplit]

Hi all,
i have a power loss with my a6 2.5 v6 tdi, at low revs 1000-2000rpm you can hear the turbo spool then as soon as you get to 2000rpm it seems to stop and it just pulls like a naturally aspirated diesel.
Put a hand held code reader and got manifold pressure fault.
checked turbo actuator and seems to be working and holding vacumn.
There is not management on and will rev over 3000rpm so it does'nt seem like its in limp mode. All charge pipes and intercooler andall ok.

read loads about MAF sensors, but also people changing them as its a common and not curing fault.

any ideas?????

[snapdragon]

It does sound like limp mode and you don't get an EML.
You need to get the exact fault codes with VCDS.
It could be turbo vanes sticking or vacuum modulator, but only guessing at this stage.
If you change the MAF, it will probably seem ok until you think it's fixed and then come back. It probably isn't the MAF as it doesn't tend to cause limp mode.