I have a 2005 ram 3500 my stock injectors finally went out at a 275,000 miles. Replace them with a set of remanufactured injectors. Truck ran good with plenty of power, but I noticed that the RPMs when you let off the throttle and push in the clutch will drift back-and-forth between 500 to 900 RPMs for a while till the engine settles. I had changed out the high-pressure fuel tubes installed new wiring harness for the injectors. Change the pressure relief valve, rail pressure sensor ,air temperature sensor and never could get rid of that rpm fluctuation. truck has 290,000 miles on it now I’ve replaced The injection pump and still have the problem. The truck is stock except for an air dog fuel system I put on it. Can anybody help me out on what the problem could be?

 

I think I have a bigger problem than the RPM bouncing up and down. I noticed that the truck is starting harder and when it starts that there’s light grey smoke and a knock in the engine till it warms up then it clears could it be a bad injector.