VW TDi 2.5 Transporter power issues

[Discover]

Hi everyone. I am new here and from NZ so thanks in advance for any help.

My 2002 van is a kombi version of the transporter with aircon (138,000 km) and the 2.5 turbo diesel. From a spec sheet it seems to be the 75kw and 250nm torque from 1900-2300 revs.

It appears to not have as much power as it used to about 20% of with the turbo sort of working near the 2800 rpm range. It does seem to rev out OK.

I have been to a turbo specialist who put a computer on it and checked all things out saying no fault codes, turbo seems fine, no blocked hoses etc, nothing that really shows up as faulty.

I have contacted a dyno tune place who say if I can get hold of the specs for the engine, I assume he means torque and power graphs he can put on the dyno and check it for me.

My question,
1. does anyone have this spec sheet which I can show to him?

2. Is there something I should check myself first, before spending the money?

He is also saying he can remap the motor for about 20% increase in power. Reading through these forums I was wondering if I also needed to put new injectors in first? or is remapping OK by itself.

Many thanks...

[AllenM]

I had a similar problem with 2.5TDI checked everything but with no joy. Eventual fix was a new Air-mass sensor. Prices quoted here in Brisbane ranged from $1000 to $350 so you need to shop hard for a good price. Now goes very hard.

[Brian Considine]

I too had the same problem & mine also turned out to be the air mass sensor - easy job to do yourself - about £55 GBP.

[Discover]

Thanks guys, seems like we are all headed in the same direction, the Air mass sensor. Obviously there are wide price ranges out there. I will need to do some research here in NZ to see whats available after market.
Have a great week....