Diesel heater Issues

[StratosFearXX]

I am wondering if your exhaust has come disconnected from the heater and that it why the fumes are being sucked in. You really need to locate the heater and have a look. Are you able to get under the van and remove the plastic under trays?

I think it's under the driver's seat and the heat exchanger or something has failed internally so it's over fuelling and mixing combustion air with ventilation air AND extra diesel.