Hi, 

I am new to the forum so be gentle! I have been given a mk4 1.9 tdi with 100k on the clock. The family have had it from new and it has been very well looked after. 

I would like to give her a new beginning and tune her up. This is a blank canvas and where do I start?

Thank you for any advice.

Depends a bit what power output it is already. There were a few around the 100hp mark (5 speed box) and the less common 130hp with the 6 speed.

 

I'd be starting with a set of filters, clean the EGR vave and turbo actuator (googling "Mr muscle vw turbo" should give you loads of how-to's) then maybe a cambelt if it's age-unknown. 

Did the family believe in regular fuel additives such as diesel injector cleaner regularly?  If not, then a dose of a good brand of this should be a cheap start