I have a 1995 dodge caravan 3.3l, that has been hesitating, sluggish, rpm's are all over the place and is pumping out black smoke that smells like pure gas. (( help )) i have changed the map sensor, coil pack, and computer. but NO change.

SOURCE: rough idling sluggish acceleration

These 4.3L W motors are common for fuel leaking inside the plenum causing them to run rough and smell like raw fuel. The fuel pressure regulator leaks internally, also the injector spider leaks and the two fuel lines feeding the fuel to the spider. You have to remove the plenum and look for the clean spot. Where the fuel leaks it cleans the oil off. Before you try this check your EGR valve. The EGR valves on these get stuck open with carbon and cause a rough idle. Remove it and look for the plunger it is a small round piece that you can push in and out, make sure it closes fully. You can also clean it with carb clean and they make a replacement gasket with a screen in it to keep chunks out of it. Start with the EGR because it is easier. The parts for under the plenum are available at most any parts store. If you have any problems just ask, and if you can not find the parts I will give you part numbers. Let me know what you find I will be back tomorrow.

SOURCE: 89 Corsica: no power, hesitates in drive, idles

Check your fuel pressure, and or injectors. You may have too much fuel getting into the engine causing it to burn rich and overheat the converters.

SOURCE: 1995 CRYSLER LHS,WONT START AT ALL,TRIED CHANGING

If it is cranking with out turning over I would check the fuel pump and ignition relay, crank and cam sensors.
Basically you need to figure out if you have a spark issue or a fuel issue. (as long as you didn't have a serious overheating problem). One way to help you figure this out is by spraying in some starting fluid while cranking the engine. If it starts you have a fuel problem, if nothing then you have a spark problem (assuming you didn't blow the head gasket from overheating and was running normally before this happened).
Based on what you've already done here are my recommendations:
No spark: check ignition relay
No fuel: check fuel pump relay (aka shutoff relay, aka fuel pump shutoff relay), crank and cam position sensors, fuel filter.
There is also one other possibility, that the timing belt snapped. You would need to remove the timing cover to check this.