Hi guys, looking for a wee bit of advice. Was travelling up from Manchester today. Thursday 11.December. heading home from airport. Weather cold and snow on roads in some areas.Car ran strong and smooth from Manchester to Gretna. Had just less than quarter of a tank of fuel and due to weather deteriorating and the thought of delays due to snow. I stopped at a garge and put in £50 worth of diesel. As we travelled up towards Beattock summit. Snow on road. car ran fine for 50 miles or so then when I tried to overtake. Rev counter over 3000 car wouldn't respond and although revs increased speed started to drop. I let off hard accelerating and she ran well again. She ran fine aslong as I didn't try heavy acceleration. Everything seemed ok then after another 50 miles or so I again tried to overtake. Revs raised to 4000 nothing happened and engine seemed to stall again slight judder. I let off acceleration and again she ran fine. Got me home without any further incidents. Can anyone suggest whats going on. The engine idles perfectly and revs perfectly when not under load. Could the cold weather 1.5 degrees or snow be the cause

When did you last change the fuel filter?

Agreed... Filter or pump?

If the rev are increasing but the car is slowing its not the engine is it ? I would lubricate you gear linkage first it could be simply slipping out of gear , very common for the linkage to get a but gummed up and stop it engaging cleanly and a simple job to do . 2008 MY Supercharged
Rimini Red / Jet
four zone climate
remote park heater
and no ugly kid windows.
magnus satis quod turpis satis

Hi guys the fuel filter was only changed 2000miles ago.

Just had this on mine, it was the low pressure fuel pump, it has been replaced with a genuine LR one and all is well again  2005 Range Rover Vogue with Supercharged Accessories
GONE 2001 Discovery TD5 ES
GONE 1995 Discovery 300 tdi GS

Agree on the fuel pump too but also check turbo inter cooler hoses, as the extra boost from booting the throttle could force open a hole which is not open at lower boost levels, reducing performance significantly. There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
KIA E-Niro 4+
2021 Discovery 5 D300 MHEV commercial

Thanks to everyone for the advice. I changed the low pressure fuel pump and changed the fuel filter. Car is now running ok.