Its not a PD (pump duse) they didnt come out until the late 2000s maybe 05 or 06?
His Golf should have a distributor pump and a pre VNT turbo.
TDI stands for Turbo Direct Injection, it does not refer to the intercooler.
The inter cooler helps both fuel efficiency and power, so leave it.Same goes for the pumps, the higher the pressure the better for FE and power. The new Mercedees diesel in the Smart is running 22,000 psi !
Check out
Fred's TDI Page. TDIClub.com. VW TDI Enthusiast Community for some good info.