Primastar injection system fault

Sounds familiar. I had something similar with my Primastar. Is it rough when you accelerate?

Indeed, there's a definite roughness, almost a hesitation, when accelerating. Did you have any warning lights on the dash, or any other telltale signs?

No warning lights. Just felt sluggish, and the fuel consumption was terrible. Get it checked at a workshop. They'll sort it.

Took it to a workshop as suggested, and you were spot on. A faulty connection in the injection system was indeed the culprit. The repair cost me 95€. The van now runs perfectly again!