[MarcusRose]

My x reg td4 has lost a lot of power. It now seems to have to get to over 3000 revs before the turbo kicks in. It used to be about 2700 before I got an injection of power, which itself was a bit painful, but now I'm having to go down to 2nd gear to get up the slightest of inclines. Any ideas? Thanks in advance for help.

 

[Disco]

Has this loss of power has been a gradual thing? If so, perhaps you need to attend to the air filter if you haven't already done so. If this is ok, they I would suspect insufficient fuel delivery problems.

 

[mankato]

Check the air control valve.

 

[MarcusRose]

Thanks for the responses. The air filter is only a few months old, so should be ok. I've just tried disconnecting the wiring to the mass airflow sensor and this seems to have done the trick. But the next question is, can I leave this disconnected whilst I get a new sensor? I understand this means the sensor will work at default settings, but what does that mean for performance?