This!!!
I would bet it is air in the system. I actually used a primer bulb on my truck when I worked on the fuel system. I had the ip on my truck rebuilt by diesel care and am very very happy with it. The truck runs better than ever.
I would pull the lines from the fuel filter and put in a small inline clear filter and primer bulb. Then just work the bulb until you have good fuel. That will draw fuel from the tank to lift pump to the bulb and push it to the IP. Once it's running good switch it back. Also with the bulb when you get the truck to start for the first tims you can work that bulb and kind of help it get going until she is happy. (Try not to laugh to much)
I had the bulb right at the tank on my truck but it will work like I said.
You could also out the bulb in the fuel line feeding the fuel filter and use the bulb until it fills the filter and then the IP. Then you can leave the bulb if you wish. I left the one on my truck. It does add some peace of mind because if you have a fuel system issue somewhere you can prime it without killing the batteries.
Also the timing marks are easy. The are on the block at the top where the pump mounts. Line them up even and run it.
Good luck and don't give up.
