Power Loss at Speed MK4 GTi 8V

[Lardybloke]

Hi, I could do with some help here as I don't know where to start looking for the problem:
The car is a 2001 Gti 8V, done 138K miles and so far has been ok mechanically. But on the last three long distance trips it has cut out whilst driving at speed, it seems to happen when the car has been sitting at 65-70 for a long time on a motorway or dual carriageway which makes me think a sensor maybe? No lights on the dash, just loses power as if the throttle has become disconnected, there's no response to the pedal and then it just cuts back in. It has only done it once per trip, but the delay in cutting back in seems to be getting longer each time, it started as a slight blip like a single missfire, then it was two seconds and on Sunday it was more like four seconds. I'm nervous of long trips now and have to keep to the inside lane in case it happens whist I'm overtaking.
Any help gratefully accepted.
Thanks

[DubNut1982]

Clean MAF sensor with MAF sensor cleaner spray, allow to dry and refit. Find videos on youtube. This is routine maintenance anyway so no great loss if doesn't work.