Well now,, that is another question! Or two!! Possible spark plug, coil on spark plug, injector or wiring problem , vacuum leak etc... it needs to be tested by a mechanic so no money is wasted on parts you dont need.
If you smell fuel (like a flooded engine) DO NOT drive it! Flashing light usually signals an injector problem. It could be as stated by the other's a spark, coil, wire type of problem., but all I'm saying,if you smell fuel, don't drive it.
I just had the same problem with my 2001 town car. Misfire cylinder 5 and when I pulled the coil off the plug it was full of engine coolant. I dried the coil boot and spring and changed the plug ( whoever did plugs last was smart enough to use never sieze on them) misfire is gone. I then added leak repair to radiator for gasket repair in case there is a coolant leak. Cost me $17.00 for the total repair but that was doing it myself, it's actually quite easy it took me about twenty minutes. Good luck.
Just wanted to add to the list, have similar problems with car jerking when it gets to about 40-50 mph. Also the check engine light flickers. I have a 2005 Lincoln Navigator and took it to a ford dealer. Bad coils 5 and 6 that I had to replace.