ok i have a 91 z28 with a 335 stroker motor and i just bought it a week ago and it won't start easliy and it is blowing black smoke out the tail pipes so it is overloading when it starts it shakes and sounds like **** when i shut it off a lst it sit no more than 10 secs it will not restart so i was wondering could this be the cts or tps i also already changed the o2 senser and the map senser so it wasn't that plz give me some info with what u guys think is mire likly the problem.

 

You should check your fuel pressure regulator. Pull the vacuum line off, if there is fuel in it, the diaphragm has a leak in it.