most likely, too much fuel.
Soot, or dry fouling of the plugs is a result of unburned fuel. The causes are (in order of likelihood) 1. Not enough air. 2. Weak Spark. Failed spark plug(s). 3. Too much petrol. 4. Ignition timing incorrect. The main thing to establish is the soot on all plugs or just one or a number. If all, then 1,2,3 & 4. If just one or two, or a bank if multi carbed, then focus on that bank.
burning oil
aerosols and soot from air polution
burning to "rich", too much fuel. This is a result of an incorrect air/fuel mix. check fuel pressure regulator, Oxygen sensor (s), and maybe PCM.
National trust crossword, im stuck on this too :))) Think it might be smut
too much strength is when you excercise, ,,,,,,,,,,,,,,,
I'd assume too much soot would build up and the truck would not start.
quantity theory: Theory that too much money in the economy causes inflation.
Soot is produced in incomplete combustion of hydrocarbons. Soot is black and leaves marks. It also causes health problems if in contact or inhaled!
When you eat too much salt and drink too much sugar
The emission output at tail pipe can be used to check causes of little air or too much fuel. The emission output can check the levels of water vapor, sulfur dioxide, hydrogen and particulate carbon soot.