Loss of power

Hello all.im having an issue with my 300 tdi auto edc. When going uphill at about 3000 revs they momentarily die off then pick up again. It doesnt do it all the time. Its like it trying to change up but dosent. Im a bit stuck with it. Any help will be appreciated. Thanks

Could be many things, start with the basics, when were the fuel and air filters last changed, is the lift pump operating correctly, do you have any vacuum leaks, is air getting in to the fuel system, is this the only problem or are there any other symptoms that might be related, has it done this for a long time or started doing this recently maybe following some work/repairs?

Hello. Fuel and air filter changed recently. A new delphi lift pump was also fitted. Havent checked for vacum leaks. No air in system as far as i can tell. Been happening for about 8 months. No other problems. Car drives and pulls well. It only happens when going up hill and accelerating. Its like when the revs drop off and the autobox changes up. The revs will die off it does not change gear then the revs pick up again. Theres no smoke.

That's strange, I wonder if it could be a gearbox problem but I don't know why it would only do it while going up hill, I suppose the throttle input in relation to the road speed would be different going up a hill compared to a flat stretch of road but I'm not sure what else would change, I assume it's EDC like mine so there will be some basic electronic wizardry going on that might be affected by throttle input but I am definitely no expert in that area, hopefully someone with a little more knowledge will help out.

Tank pick up pipes under boot floor pulling air in due to rusting through
Accessed via a panel under boot carpet

Hello thanks for the replys. Tank pick up pipes are ok. Put into 3rd gear still did the same. I cant figure this one out. Drives fantasic. It does seem fuel related but revs drop of momentarily then pick back up.im a bit stuck with it