Im at my wits end with this early 99 7.3. Ive been fighitng this problem for over 2 years now, when its warm, the truck runs awesome. When I bought the truck, it would white smoke when you started it until it was warm. Asked the dealer about it, told me it was normal, it had bigger injectors and a chip in it. This was my first diesel, so i was a dumbass thinking it was ok. That fall, the truck wouldnt start on its own under 50 degrees. So i changed the gpr and the glowplugs. Helped a little but not much. This is my plow truck so no matter what, it has to be plugged in under 40 or it would drain the batteries cranking it. So i left it alone all last winter and this year until about 3 months ago. I was tired of it smoking all the time when i started it, doesnt matter what the temp. So i went ahead and replaced the gpr and glow plugs again as well as the valve cover harness. I did an ohmn and power check at the plugs and it all checked out fine. So with my scan tool, i started checking the hpop pressure and the ipr duty cycle. All that checked out with all the info I could find. I took the ipr apart and cleaned it and also checked the icp for oil in it and nothing. I also checked fuel pressure and it was 60psi. So after asking some powerstoke guys and the local ford dealership diesel tech, they all told me the same thing, I had bad injectors. So I did a buzz test and cyl. balance test and the only thing that was suspect was #8cyl failed the contribution test. So i changed the grey cps to a new original black International one and It passed the test. So i yanked the injectors out, took them to a repituable diesel shop, had them check them out on a flow bench and was told 4 of the 8 were bad, they didnt have enough clearance. They said the other 4 were ok, but could use replaced. Didnt have a ton of money so I bought 4 new injectors and reused the other 4 with new o-rings on them and re-installed everything. At that time, I also put new gauges and replaced the superchips 40hp chip that was in it with a new TS 6 position chip. Also put 2 new batteries and a new 2003 7.3 high torque starter in it to spin it faster. Did a compression test and all cyls. were between 360 and 390 except #5 and it was like 200. The turbo fins are not beatup or worn down. Didnt do a leak down, but the truck has blow by, it has a catch can with filter on the ccv and you can see the puffs of smoke coming out it when its running. Got the truck running, drove it, and still had hard start and white smoke. So I took it to a local mechaninc who specializes in 7.3's and he diagnosed it and said it still had at lease one bad injector or more but he couldnt tell me which ones. Asked him about low compression, and he said that my numbers wouldnt cause it to smoke so much and be so hard to start, he had seen a lot worse. Also said it runs great and had a ton of power so It wouldnt be a cracked piston or hole in a piston. So I figured it was one or more of the 4 old injectors, so I bought 4 remanufactured injectors that had new barrels and plungers installed and had a year warranty, figured they would do the job. Installed them last night, took the truck for a drive, definatly made the truck more responsive and drive better and when i got back to the shop it wasnt smoking, but went out this morining and its like 55 degrees, and still hard start and white smoke. Also, the truck has no codes or SES light on. So WTF, Im totally beathing my head against a wall. Ive spent all this money and time and still have the same problem. I know im new here, but PLEASE HELP ME!!! I know this post is long, but I REALLY appreciate everyones time reading it and trying to help me out, THANKS in advance for everyones time!!!