Had a similar problem with my 2010 after shimming the fprv . Could not get it to seat correctly no matter what I did . Just crank and crank . Finally just bought a full plug from xtream diesel and it's all good . Don't know what went wrong with the fprv but it would not quit leaking . Had half a bottle just cranking no start . Drove me nuts ! I used some washers and shimmed it fully and took the spring out to get me by tell my plug came and once in awhile would get a reduced power with the temp fix but I was able I drive it . Good luck hope this helps !
I already eliminated the fprv.