What causes a misfire can be a number of things. But from what you are telling me, you may have water in your oil and maybe some bad gas inside your engine. If you have pumped in some bad gas, you may have a filed out the sparkplug at that #8 cylinder.
It could, depending on the cause of the misfire.
"white smoke" is steam, which means coolant is getting into cylinders. usually means cylinder head gasket or cylinder head is faulty
you have a blown head gasket .
What color? Blue- burning excessive oil - bad rings or valve Black - raw fuel - cylinder not firing - carb adjustment White - when engine is at normal operating temperature - steam bad head gasket?
When a steam engine's fire is burning efficiently, it produces very little smoke and what you are really seeing is white steam. When coal has just been added to the fire, or the fire is burning inefficiently (perhaps too much coal) it produces grey or black smoke.
generally white smoke means water or antifreeze is entering the cylinder wich means either a blown head gasket or corrosion damage in head water jacket causing leak into cylinder
Injectors, timing, low cylinder pressure.
The "white smoke" you see coming out of the tail pipe is steam. It is a pretty common occurrence in the winter or early in the mornings when you first start your vehicle. If your "white smoke" does not disappear after a few minutes or after driving a few miles, you may have a blown head gasket (or worse, a cracked cylinder head) that is allowing coolant to get into the exhaust system. A compression check on the cylinder head will help detect/determine if the steam is due to a problem there.
The white smoke coming out of a tailpipe is called steam. It is caused by water leaking into a cylinder. It can be caused from a blown head gasket letting water from your cooling system leak into a cylinder. When the gasoline and air burn, it makes the water in the cylinder turn to steam. The steam goes out your tailpipe with your exhaust gases. If you do not keep your radiator full, you will blow your engine. If you do not get it fixed, It will ruin your lubrication system and ruin your engine. Hopefully, you are in a position to make car payments. Can also be moisture trapped in the exhaust system if you make too many short trips and never get the entire system up to temperature. Blueish colored smoke would be buring oil, caused by failed seals or rings. Black or brown smoke is gasoline. caused by too rich a mixture.
White smoke is steam It may be a early indication that the head gasket is failing.
If the check engine light is blinking , that indicates a cylinder misfire has been detected White smoke coming out of the exhaust ( especially when the engine is warmed up ) indicates that coolant is getting into an engine cylinder from a bad head gasket , a warped or cracked cylinder head
Make sure the timing is correct and the plugs are all new. If that doesn't work, make sure the plugs are getting spark and that the air/fuel mix is correct. If the car is smoking white smoke take a look at both heads and make sure that both heads look good (no cracks in the head or bulging/broken gaskets).