When did it start doing this? Before you installed all those parts? If it started after you installed those parts, check your new parts against your old parts. (cap & rotor!!) Make sure you put the cap on right with the plug wires in the correct firing order.
If it happened all of a sudden while you were driving or starting to drive it, there could be a timing chain problem. Although, you have not mentioned what engine it has so it's hard to say what else it might be.
If it has a catylitic converter, that could be plugged. Check fuel pressure by disconnecting the fuel hose to carb and inserting that business end into a bottle and crank the engine for a few seconds. As mentioned before, deisel bad - gas good (LOL)
Check your oil. A guy last week said almost the same thing and found out his oil filter had a big hole in it and all the oil in the engine was gone. Too much friction - bad....
Will it rev up in neutral? does it backfire? does it have good spark? You sure you got the plug wires right? that's about all I can think to check.