Ok I am working on a friends truck and I am stumped. Here are the symptoms, first start of the day takes lots and lots of cranking to get it to start. Once it does start it runs fine and will start normally the rest of the day. We r&r the lift pump with a new one, no change. Then we found the pickup line was sucking air at the sender at the tank, fixed that. Same starting issues but only seems to do it in the morning now.We tried pinching off the suction line as close to the tank as possibe to eliminate the possibility of fuel draining back, no change the next morning. Now here is the part that makes me scratch my head. When it is having this no start thing happen, we get good bubble free fuel out of the bleeder screw on top of the fuel filter housing but no fuel at any of the injectors. I have had all 6 loose before and it took a good minute of cranking doing it in 20 second on and 1 minute off intervals before it started to push foamy fuel out. The foam clears right up and if I tighten the injectors it will fire right up cough and pop for a couple of minutes then clear up and never have another problem the rest of the day. I know the solenoid is pulling all the way up. I will take any and all help this is really becoming a PITA.Thanks. dan

 

Check the return line at the rear of the head.
They have been known to crack, let air in and NOT leak fuel!!! I slid the hose on it another 1 inch and solved mine.

 

Dan is talking about my truck. i farted around with it tonight and i thought maybe it wasnt rolling over fast enough so i took the 5 year old batteries out and stole the brand new ones out of my dads power joke and it started right up. but the moment of truth will be tomorrow when i leave for work. ive been having to rely on my 6.5L. as dan mentioned i fixed my sending unit but only a temp fix could anyone point me in the right direction for getting a rebuilt one with out having to spend $450 for a new OEM thank u very much

 

it acted great yesterday with the new batteries but this morning it was back to the same old pain to start. the previous owner had the IP set 20deg advanced, when the guy with the tools gets home from vacation im hopeing he has time to take 4.5-5 deg out of it. do yall think thats why its starting so hard? everything that dan posted is what we have done to try and diagnose but we have ran into a brick wall with ideas. any ideas? thanks Mike

 

On the cold start condition, manually prime it before you try and start it, make sure you push the fuel primer plenty of times after your hear the overflow valve start to sing.

Then if you still have a hard start we can rule out loss of prime.

 

Had the same problem on an old Ford IDI diesel, didnt leak fuel. Let it set for a long duration of time, like overnight, and it lost prime. You are getting air. Start by replacing EVERY fuel line on the truck from the tank to the IP. And the returns on the injectors. That SHOULD fix it. The sendor is the first place I would start, I think you found your problem right there. Get that done and see what happens