Nissan Repair: Nissan serena excessively consume fuel, nissan serena, 5km

Question
My nissan serena is consuming excess petrol and the plugs have black soot building up. I have recently changed all filters and oils. The exhaust is black sooted. It have signs of running rich bt l am not sure why. I have done the diagnostic and everythng appear fine except for the distributor that is -20. I exchanged the distributor with the bluebird distributor. Could this the problem. I am getting 6.5km/litre and the van is underpowered in hilly arrears.?

Answer
Hi Madziva

That could very well be the problem. I do not understand the -20, though. Is that the timing? 20 degrees before TDC? If you are experiencing loss of power up the hills, and your plugs are black, I think the timing is retarded, again because of the distributor.

Why was it exchanged?

Hope this helps -
aloha
calvin