My plug on #3 cylinder keeps runnign really rich, I have replaced the plug a couple of times thinking it was just bad plugs and I just bought new plug wires the other day because they have not been changed in awhile and it is still running rich and turning the plug black but only on the one cylinder I have also noticed that it is not wanting to stay running right it idles good for a few minutes then it wants to die the idle slows way down. Do you guys think it is a coil pack causing this?

 

you might have a stuck open injector... thats what it sounds like to me anyway. i bet it runs fine at highway speed, but at idle it wants to idle rough and piches black smoke...

 

It pitches some black smoke but its not running that great on the highway either it kind of spudders and feels like its loosing power. I do have 60# injectors thought.

 

yeah, its probably trying to compensate for running so rich by cutting fuel back, so the one still gets too much and the other cylinders starve... i would try switching that #3 fuel injector with another one and see if the problem switches with it.

 

just so you dont spend the money on it if thats not it....

 

Coilpack or injector and possibly plug wire. Move things around 1 at a time and see if it follows.