air in fuel lines?

Hopefully this is a simple problem...

I've just completed my first engine transplant in a type 3 and I've started to venture out on the local streets.

It runs fine on the flat, but going up a slight hill with just a bit of load on the engine I get pretty bad judders and loss of power.

Is this a fuel problem - possibly air in the line/pump? If so will it just work itself out in time? Carbies are not fully adjusted yet, but I get the same problem with two different sets.

How much fuel was left in your tank? usually up a hill its a 'running rich' issue with the carby flooding... & that would cause splutters for sure.Thats why alot say not to park a vw angled up a steep hill for a while. so i've heard....

This is stuff i have 'overheard' on the grape vine... don't quote me. i could be absolutely wrong.

But you say you tried two sets of carbies.. hmm...
Your putting your foot down obviously moreso on this hill?