Series 2 - Lack of Power

Once again i call upon the superior knowledge of this forum for an idea of what's up with my Discovery Series II!
I internmittently suffer from a lack of power, almost as if the turbo is not working. The engine will rev to 3000 rpm but then just goes flat & I can't accelerate any more. I also notice that I lose speed on hills when this condition occurs. There doesn't seem to be a misfire, there just isn't any power. It happened today on my outward journey but cleared when I was on way back & it all seemed to be fine again.
I replaced the air filter a few weeks ago so it should be breathing ok. I'm stuck for ideas, anyone help?

try checking the injector harness for oil contamination. Check it at the red plug on the engine management ECU

Try your air flow metre, sounds just like what happened to me.

Thanks, what am i looking for on the red plug? signs of oil?
With the air flow meter, I assume this is a straight swap & not something I can test without a diagnostics tool?

Only suggestion I have is to put your location into your profile so people nearby can offer to help - e.g. me but hardly anyone is nearby

Thanks Dave, good thinking.
I'm in Coventry!
Jez

Try unpluging the air flow meter,and going for a drive.Ecu will run on default settings,so see if it improves,if it does it probably a f*cked afm.

Im Simple Terms

MAF / MAP / De Cat & EGR then ya sorted ... if not your truck is fubar and Id say get it in to the nearest garage

Would seem to be connected to the MAF. Disconnected as advised, went for a drive & what do you know.....pulled cleanly & revved in every gear! Thanks for the suggestion Jon, it's much appreciated.
Anyone suggest where I can get a replacement MAF without mortgaging my house?
As I have owned the car 8 weeks & had a job to do every weekend! I have to assume that this is setting the tone for Disco ownership & my weekends will now be taken up working on the car!

Replace with a genuine one,around £70,pattern ones dont last as long and have seen incorrect readings on non genuine.