5td transit lwb. My first time away in it and driving around doors it seems to lack power. Drives ok but as soon as a hill or slope is reached slows markedly .seems to also struggle to pass 60mph is this normal or is there a filter or something that I need to do to release more power
A 1990's Diesel Transit is never going to be a rocket ship, especially when fully laden, as even the top end ones only had 113bhp from new.
Saying that, there are a few things you can do on almost any vehicle to help - the first, and most important, is to give it a really good service - replace all the filters (oil, air and fuel). Clean or replace the injectors, and check all the fuel lines for any signs of perishing, blockages or restrictions. If it seems like it has been neglected, give the oil a good flush through, and replace it (and the filter) again after a couple of hundred miles.
Make sure the turbo is in good condition too - any signs of black smoke coming out the exhaust should ring warning bells. Check the fuel pump too - I'm not sure which type the Transit has, so I can't say if it's user-mainainable or not.