Ok so ive been dealing with injector issues and tryck finally was runing good but on start up only if its sitn overnite or when im at work for 8-10 hours. When i start it it will shoot out a puff of greyish colored smoke then about 5 seconds later the rpms will bounce up and down and sometimes actually bounce so low it will stall out.its a 2005 f250 6.0l with about 170000 miles. It will bounce for about 2-3minutes and if it stays runing then it smooths out and runs like a new truck. In the last month ive replaced 2injectors thermostat oil filter fuel filters oil a couple diffrent sensors. Wasnt sure if anybody else has expierianced this type of problem.