Power loss when mid temperature

Hi Just been towed back from Cornwall not happy my Landy d2 51 plate when reaching mid way on temp is fine soon as it reaches middle of gauge it starts to lose power and will not pull at all, also stopped off over night reached mid temp when stationary started too do the same as if there was no fuel getting through AA could not find anything wrong removed MAF cleaned cam sensor still the problem
Any ideas

Temp sensor, thinks its overheating.or maybe the expensive alternative cracked head.

I ha a very similar problem with mine but it only happened when towing.

From memory there is quite a big range in temp where it doesn't show on the gauge. Ie the gauge doesn't move between 90 and 110 deg then suddenly shoots up when it sees a height temp, that then cuts the fuel off because it thinks its at a critical level.
I tried changing every sensor possible, new injector washers etc and finally settled on a cracked head.

Thankfully before spending money on a head, I got a new Alisport Intercooler at Bristol and west last year and set to fitting at the show with some fellow LoonyZoners... When the Radiator was visible it was blocked and in bad condition. I washed it out and the problem got better, so replaced it when I got home and the problem was cured and saved me a fortune.

In other words have a loom at your Rad, can you get a Nanocom to check actual temp?

Thanks for the info had a new head gasket last year checked the water res full and still had pressure an no leeks anywhere was driving for a good 20 min .
Will also have a look at the rad
Thanks guys