TD5 Defender

[nakedbarra]

I have a 2000 TD5 Defender new to me and it is seriously low on power, Compressions are all between 280-300psi, Maf is new and helped a little, waste gate is fine, Head was recently done right before I bought it and my concern is that the timing chain was installed a tooth out creating the compression to bleed of prematurely? your thoughts?
It idles and runs smooth just very slow to accelerate / rev up and is overall lacking a lot of its torque.
Could it be the timing out after the head was reinstalled?
Previous owner said it had all the power when it went in for the head gasket replacement done at a shop.
any help would be great as this is getting frustrating and expensive to diagnose with no answers.

[shack]

Do you have any diagnostic gear?

It's certainly possible that the timing is out, it could also be other things, but a bit hard to tell.

Do you know what version ECU it has? If it's the early one (MSB) then a new MAF won't make any difference.

[TonyYates]

Have a look at the turbo hoses. They can delaminate and collapse under load, throttling the turbo. Silicon ones are a good replacement.

[AK83]

also could pay to check

bump stop clearances for the injectors ... not unusual for those to be done incorrectly.

fuel pump/fuel pressure.

turbo pressure. can you hear the turbo whistle at all? as you build up speed(or load on engine) the turbo whilst is more than obvious.
Could be simple thing like loose clamp or slightly askew hose fitted and losing pressure from the turbo.