Bosch pump

[ally406]

With an IDI engine like the XUD, the fuel is not injected into the cylinder, so the uncombusted veg has limited contact with the rings. With DI engines this is obviously not the case, and when starting from cold you have incomplete combustion which causes a build up of polymerised veg. Think of the edges of an old frying pan, that's what's accumulating on the rings. Some folk never seem to have a problem, others get gumming issues after 10,000. Your mileage may vary, literally. The general advice is usually to twin tank a DI motor to avoid problems.

Plenty of XUD around anyway, got my 406 for £325, 99.9% of the time they have Bosch