Slow to start - W900

There is a check valve in the return line close to the head, if it doesn’t seal rite you will lose Prime, if it complete fails you’ll need ether to start it.

 

Well..barring,filters or fuel pump...I would probably lean towards "worn injector cups".Is a lot of miles on the clock? Had some Volvos do this.Just my thoughts

 

I had the same problem with my 60 Series. I have a Davco fuel filter housing with the clear dome. Turned out to be that the lock ring was overtightened causing the o-ring to distort. This allowed air into the system whenever the truck was shut off for more than a few minutes. If you have spin-on filters it could be either loose or overtightened. Start with the cheap and simple and work toward expensive and complicated.