first noticed the rough idle when I exited the freeway, some black smoke, drove it home, 60 miles ran smooth at highway speeds, so I went ahead and replaced all the injectors, 2000, miles on engine since rebuild, but didn't do the injectors or IP still hard to start and rough Idle some Black smoke Tail pipe caked with carbon,I found a small 3/4'' long screw allen head, laying next to the #2 cylinder glow plug while changing Injectors. is this a IP sending to much fuel??? any help would be appreciated Thanks Mudguts

 

Ummm.... lets hope that allen head screw isn't the one thats supose to be in the IP on the side to adjust fuel flow....


Black smoke is simply to much fuel for the amount of air getting in, so yes, the IP is overfueling the engine.

 

Check and see that the advance plunger on the pump isn't stuck. Follow the arm on the drivers side of the ip, the plunger is at the end make sure the arm is always in contact with the arm. If its not the plunger is stuck, thus screwing with the timing