Has anyone every had a bad (weak/leaky injector)? Here is the reason I am leaning to some injectors.

Well after 88k miles and 1K w. a cc306 I think my injectors are dead. I have had a rich condition causing the car to smoke/puff raw gas. I pulled the headers looking for a crack becuse I was getting a lean indication. In the exhaust port on #2,4 there was a dark wet substance that looked like tar. Wiped my finger through it and it smelled like gas. I swapped the injectors earlier this week so I pulled the other header. The #1,3 cylinder were the same but drier since the injectors were put on the other side. I am taking the injectors to a shop to see if thats what caused it.
Sorry for it being so long.

Chad