When I bought my new to me 1993 F350 IDI Non turbo a while back it was blowing blue smoke so I decided to do a few things...installed new return lines, added a electric fuel pump and a rubber filter to pump kit(the hard line fittings were screwed up)...I also installed new Motorcraft glow plugs(4 tested bad)...when I started it the engine started right up and no smoke...then a minute or so later it started to blue smoke and run rough....the first video is it running on fast idle...the second on slow.....the PO had recently changed out pump and injectors...I haven't done the loosening of individual injectors yet but thought I would see what you guys think...
https://www.youtube.com/shorts/JWtci0-nWGs
https://www.youtube.com/shorts/Zc2cjwesRiA
https://www.youtube.com/shorts/JWtci0-nWGs
https://www.youtube.com/shorts/Zc2cjwesRiA