1st Gen cummins not starting
 

Ok so i put a 1st gen in my 85 Chevy, got everything buttoned up. Primed it and it fired right up it was doing good for about 2 or 3 weeks and now if it sits for any amount of it wont start. it wili act like it wants but nothing. if i crack the injector line and bleed them it will start and be fine for the day. But the same thing the next morning. so if i am getting air in the lines how do i tell where its coming from. Thanks

IP leaking at all? New lift pump or no idea?

https://cimg0.ibsrv.net/gimg/www.die...aa6342d687.jpg
I looked in my dodge service manual. Here is all it lists for starting problems