04 lb7 cranks but won't start

[BgBlDodge]

My mom has an 04 LB7 that will crank fine but never start. All 8 injectors were replaced earlier this year. Truck has ~170k miles on it. Last week it did this and the shop replaced some kinda low pressure fuel module and a glow plug and it has worked fine until today. Dad used the little manual hand pump and bled a little air out of the line. Tried starting it but didn't work. Towed it 5 miles to the shop and tried to crank it there and it hit first time. I'm thinking there's a leak in the return line or something that's causing this. No check engine lights the first time this happened or this time. Any ideas? Thanks.

Tyler

 

[JD4440]

check the filter housing for leaks, make sure the water separator isn't dripping.

 

[BgBlDodge]

Found a couple of leaks on the filter housing and fixed them but it's still doing this. Started doing this when it started getting below 60* at night.

 

[phale]

The filter head itself may be cracked. Try pumping the primer while someone cranks the truck to see if it will start. Do you have a scanner so that you can verify it is not making rail pressure? there are electrical issues that can cause one to crank and not start.