I have a mulit port 2.8 that will run for like 5 seconds and die last time out I popped a coolant hose so it ran hot for like 5 minutes or so got it home and it ran ok but sounded let a desiel and would not reve up ... I repalced all kinds of crap and there is no ob1 plug spot because half the wirring has been changed because it's a camero motor. has good fuel pressurer and spark but it is making the plugs black with unburt gas . I would just change it out but with a wife and two sons I have to save up for Christmas , just trying to get it going agin until funds get better. Could it have abad head or intake gasket causing it to do this Thanks so much for the help....

Do a compression test.