I have a 2005 Dodge Dakota 4.7 V8. For sometime now this truck has had a Cylinder #7 misfire. The truck now has a new engine installed, New #7 Injector, New #7 Coil, All new NGK plugs, New EGR Valve and New PCM. But the truck still has a cylinder #7 misfire. I even swapped the intake on the truck. This is a dead miss. If you unplug the coil at idle it makes no difference on engine shake. After the engine was installed the truck still had a cylinder #7 misfire. It would gas soak the plug in a couple of miles. After the new PCM was installed and new injector the plug looks ok after driving. I just preformed a compression check to see if something was wrong with the new engine and all the cylinders are within 5 psi of each other. I never get a random misfire code just #7 misfire. No other codes even with the new PCM. I don't know of anything else that could make this truck only skip on 1 specific cylinder. Has anybody ever ran into this problem? The truck only has 71,000 miles on it and the new engine has 800 miles on it.

 

Since you replaced everything else.... Time to check the wire harness for the cylinder 7 coil, and injector. Think I would start with the coil, as the injector appears to be actually working.

Moving this to Third Gen Dak section for ya.

 

Tried straight wiring new connector from coil to the Brown wire on the computer (bottom black harness) Red wire straight to the battery. Still has a skip on #7. I just put a new fuel pump on it and that helps with the lose of power a little bit. Inside of gas tank was clean as a pin. No dirt or anything of any kind. A new problem that it has is under heavy acceleration it falls on its face and the whole truck starts shaking. Even with new pump. But only on a steep uphill grade and heavy acceleration. Then the check engine light blinks with a door chime sound. The only code even under this condition is Misfire Cylinder #7. When it does this the power to the truck cuts in half. No power at all. It's hard to believe this is just 1 cylinder skipping. I have also put on 3 of the 4 o2 sensors. Both on the Cylinder #7 side and the downstream on the pass side. No change cylinder #7 misfire. I don't know what else it could be. Fire, fuel and compression . But still a misfire on that cylinder. I also put on brand new fuel injector pigtails (Soldered In) on the cylinder #1'3'5 and 7. I'm about $6000 in this repair with no real solution. (New Motor was caused by overheating. radiator blow out at 80 miles an hour.)But it had a skip before this happened.

 

The truck doesn't have a true dead miss now. It will smooth out and then quiver from time to time and the longer you sit at a red light the worse the skip gets. Checked the plug again. No gas and it doesn't look fowled.