1988 Volkswagen Eurovan excessive fuel consumption.

Hello all. Happy new year.

so here's the deal, I have an '88 vanagon. And i've been reworking it because I am very deeply in love with it.
it goes through a lot of gas for a v8 ford, let alone a 4 cyl volkswagen. But the engine is good, save a slightly iffy head gasket, and I just replaced the whole fuel system (except the injectors) because I found a leak.
which aren't that uncommon if it's never been replaced.
anyways, the fuel consumption hasn't really changed. I'm averaging about 5-7 km/per litre.
which is phenominally bad. Ha ha ha. Apparently they can still hold their own at around 16- 19.
pah.
so, to the point, would all this be caused by the fuel pressure regulator?
cause i'm out of ideas.
cheers, and the best new year to you all.

. Jess.