Archived Starts, stalls, hard to start, then runs fine

[tamaracram2500]

2001 quad cab 4x4 automatic, 194 K miles.

Over the last two weeks. when I start the truck first thing in the morning, it starts, and then stalls. About 15 seconds of cranking and she starts and runs fine. It only does it first thing in the morning, the rest of the day its fine.

I have a Blue Chip Diesel low pressure fuel light tied into the fuel intake on the injection pump. The light is normally on when I turn the key and let the manifold heater warm up and then goes out immediately as soon as it starts. That is the case today. I can hear the lift pump running as it should so I know I have fuel to the pump. The low pressure light NEVER comes on when Im cranking or when its running. Oh, about 1000 miles on the fuel filter.

Just like a toothache, I know its not going to go away. Im afraid that it will just die on me in the left lane at 70 miles an hour. Is that a possibility? Thanks in advance for your help.

Pete

 

[JR]

It sounds like air is being introduced into the fuel system somewhere. It is a fairly common occurance, but sometimes finding the culprit is not so easy. What generally happens is the truck sets for a while and the fuel siphons back into the tank courtesy of a minor (sometimes VERY minor) leak. When you go to start the truck the truck will run briefly off the fuel that is on the high pressure side of the injection pump but as soon as it catches that pocket of air that has been introduced into the system the truck falls on its face. Then you spend the next several seconds cranking the engine over, the truck bleeds itself out and your good to go until the truck is shut off again and allowed to sit for a period of time.
Next time the truck has been sitting overnight, bump the key to activate the lift pump and crack the drain valve open on the fuel filter canister. Do Not start the truck. You should be getting a good stream of fuel for several seconds while the lift pump is running, if at anytime the flow is interrupted or it starts spitting air you have found your problem. You may have to prime it like that once or twice until you have a solid stream of fuel and then your truck should start and stay running. I would verify that first and then we can either begin tracking down the source of the leak or move on to other troubleshooting.

 

[Missouri Mule]

I agree with JR air in the system. Check the rubber return fuel line.
You won't get fuel pressure until engine is running. Lift pump doesn't run when your cranking but will run after you crank for 25 seconds filling the fuel filter canister.
The VP44 can not take the fuel pressure unless engine is running.

 

[Missouri Mule]

I agree with JR air in the system. Check the rubber return fuel line.
You won't get fuel pressure until engine is running. Lift pump doesn't run when your cranking but will run after you crank for 25 seconds filling the fuel filter canister.
The VP44 can not take the fuel pressure unless engine is running.

 

[Sticks]

Return line from the VP, the "T" fitting at the back of the head, and the quick connect fittings down where the block mounted lift pump attaches.

You can hope that any leak that you do have has managed to leak externally and has collected some dust/dirt, so look for buildup at the connections.

I would advise against using the water drain however, especially if you have never replaced it, or the O-rings, unless you actually follow the owners manual and use it to drain the darn thing of any water every time you fill up and change the filter, then it might seal back up.

Better off to use a 17mm or 19mm wrench and crack open one of the lines (banjo bolt) between the filter housing and the VP. Personally, I would crack open the return side of the VP when bumping the starter to cycle the lift pump.