No spark to #2 cylinder

Ordinarily, rough running with a raw gas smell indicates a fuel pressure regulator or fuel injector problem, but that usually produces grey or black smoke. The white smoke may be steam, which is more serious.

If the exhaust also smells somewhat like maple syrup (that's what burned engine coolant smells like unless you are running water without antifreeze), or your coolant level is going down rapidly, you probably have a bad head gasket, cracked block or head that is leaking coolant into one or more cylinders. That's what would produce a large amount of steam, and the uneven power production is what makes the engine vibrate strongly. The mixture control system is being all messed up because the coolant in the cylinder is preventing proper combustion - on the one hand the knock vibration sensor is telling the computer that the engine is running too lean, but on the other hand the oxygen sensor is detecting the rich condition. A readout of the engine computer would be interesting to see.

Run the engine as little as possible until you get this checked out. A coolant leak into a cylinder can cause quite a bit of secondary damage.

You may be able to identify which cylinder has the problem by removing the spark plugs and inspecting them. A wet spark plug is confirmation of my hypothesis. If you have a borescope (video camera on a flexible tube or with a fiber optic bundle with a lens on the end), you can peek inside the cylinder through the spark plug hole. Otherwise, pull the head to see where the coolant leak is.

black smoke indicates oil getting into the cylinders , get the compressions tested as a first step

Carburetor is allowing too much fuel into the engine. Could be a sunk float, mixture screws have been improperly adjusted, even a plugged air filter can do it.

Sounds as if there is one or more cylinders misfiring. Possible defective ignition coil/spark plug/s/ or ignition wires. IS the vehicle blowing black smoke out the tail pipe? If so, another possibility could be an over fuel situation caused by a defective sensor or leaking fuel pressure regulator. My guess would be a mis fire causing the engine to not fire on all cylinders

It's running extremely rich. Have the fuel pressure and fuel pump checked.

You have a failed head gasket

Major repair

Hope you didn't think the stop leak was
a genie in a bottle,never need any product
in any vehicle,just the proper repair

White smoke was coolant ,should have known that

My guess would be a leaking intake or head gasket. Water in the cylinder(s) is shorting the spark plug until the temp comes up on the engine. The white smoke is the coolant being burnt off. check your coolant level it may be low.

Black smoke is from too much fuel, or a mis-firing of the spark plug. Pull all plugs to look to see if one is blackened. If so, this is your troubled cylinder. You can test each spark plug wire with a High energy spark plug tester. If that looks OK, then do a compresion test to see if the mechanical part of the engine seems good.

Black smoke means "fuel not being combusted" or "runnig rich". I have no doubt you have gasoline. Your spark may not be burning the gas. Is there a check eng lite? If EGR was sticking, you would probably get a check engine light for this. If your truck has a Vortec design, I would find out if you need a new "spider". What is your mileage? Are you due for a tune up? What spark plugs are you using? Vortec? "Not all the time" sounds like intermittent. When was the last time you changed the fuel filter? Can't hurt to change this. This would be the actaul starting point for me. I would change the fuel filter which is under the driver under the chasis. You will need a 16MM and a 20MM. USE ONLY LINE WRENCHES. You may need a fuel line disconnect kit too depending on your model. Notice it only happens on acceleration? that is when you are forcing even more fuel thru the system, but not enough of a fuel stream make cause sputtering and when the fuel comes thru too rich that would be the black smoke. It sounds like you have the 2 extremes. is there afuel regulator on your vehicle? If so, you may need to change that too. Good luck.

Have you taken a spark plug out yet? You may have fowled them out. if they are not clean and have a whitish tone to them, then they need to be replaced.