My truck starts hard after a couple days of sitting, like I ran out of fuel. I read somewhere about a loose fitting or something that can cause this but can't find the thread now. Is it possible the fass is bleeding off pressure? I don't see any leaks or weeping anywhere.

Try leaving your fuel cap loose. Others say the return line on the back of the head

There's the fuel return line ........back of block .....  guess with air leak it could be draining back or letting air in the system.

Not sure how you would pressurize to check.

Did you voltage test the batteries if something has a draw on them ?

Two BRAND NEW batteries. I will check the fitting at back of block.

Two BRAND NEW batteries. I will check the fitting at back of block.

It's not a fitting it is a rubber hose. On my 12V truck I would need about 12" of 5/16 hose and about 12" of 1/4" hose to fix the leaks. You won't always see a leak but they can admit a small amount of air.

If you guys are talking about the fuel return line that comes from the back of the head, on mine it's a steel line that comes off in a banjo fitting. I have heard that banjo can start leaking. You just need to change out the copper seal washers and you're good to go.

Ya its a metal line not rubber. I still cant see how it cause a hard start, i need to look at a drawing to see how it works. I guess if you have bad connector tube o-rings it will do the same.

Think means its a metal line that connects to rubber line to return to fuel tank. Normal leak is at the fitting or more often as he mentioned in the line itself.

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Edited February 10, 201411 yr by mopartechnician

How "hard" are we typing here exacty???  Have you tried cycling the grid heater twice before starting??? That'll also give the LP a chance to re-prime the system if it did drain down.

Should start right up no matter how long it sits. I know exactly what he is talking about

Try leaving your fuel cap loose. Others say the return line on the back of the head

is this go from the back of the head down the driverside of eng to injpump ? my y2k has started hard starting too after sitting a couple days.

I had the same issue with mine. Replacing the sealing washers on the return off the back of the head and the orings in the return tee(where the two return lines join) stopped mine from doing it. When mine would hard start I could bump the starter and let it cycle once or twice and it would start no problem. From what I read here and elsewhere was that air getting into the system would allow fuel to flow back into the fuel tank from the high pressure side. I always figured if my lift pump can push fuel thru the VP that air in the system could let some of it out. I do know it sure fixed mine. 

 Another thing I tried was parking the truck in a nose down position to elevate the tank and the few times I had some where to do that it seemed to work. No hard start when parked that way any how.

 

 

 

 

 

 

Not saying this is definitely the problem, but it did fix mine.

Edited February 10, 201411 yr by dripley

ok so looks like i may need to replace orings and sealing washers can somebody tell me what size they are ?

I got mine from a Cummins dealer. Just told them what I needed and paid the man. 

THANKS DRIPLEY

You are welcome. Let us know it works for you.

Cannot see any leaks at the back of head.  Tightened up some clamps along the fuel line from pump.

Doesn't matter how many times I cycle grid heaters-etc. Same issue, cranks until get air out of system.

Have you tried cycling the lift pump? Just bump the starter(no engine start) and let the lift pump run. It runs for about 25 seconds. When mine was having the problem this would help a lot. Sometimes I would have to do it twice.

I did not see any weeping at the head on mine either, but did have leaking at the return tee. When I took the return line off the back off the head the rubber sealing washers were hard. They looked like a regular washer and hard as a brick. I had to look at them with a bright light to be able to see the rubber, couldn't feel it with my fingers.

Yup, cycled pump. Still the same. Where's this "t" in the return line?