03' 6.6 Stalls after starting - Priming Fuel

[cdgibby]

Recently truck would stall in mornings after starting for 10-15 seconds. Pump/prime fuel filter would get it to restart. Changed fuel filter, problem went away for 3 weeeks, til last two mornings, the frost hit and problem returned. Starts for 10-15 seconds and stalls. Now the pump/priming will get it to restart but only for another 10-15 seconds and stall again. Less than 1000 miles on this filter, the new Raco fuel filter. Eventually engine will stay running after the engine temp reaches somewhere around 90-100 degrees according to Edge monitor and 7-10 pump/priming sessions. Some air bubbles out of top of filter cap on an electrical input to cap, not sure what it is.

New to the forum, looking for some help. Ideals are air leak in fuel line somewhere, hope its not an injector issue read so much about, what is this additional fuel filter issue I've read about? Seems to happen in the colder mornings, if you consider Central Calif cold. Does not happen again all day long until the next morning after setting for 8-10 hours. Any help is appriciated.

[DmaxMaverick]

Welcome aboard!

Sounds like your filter assy needs to be replaced. The electrical input at the top of the filter is the heater. If you are seeing "bubbles" from there, pressure is leaking out, and likely leaking air in while it sits, and the reason you are having the problem. There's no repair for this I'm aware of, other than filter assy replacement.

[More Power]

Recently truck would stall in mornings after starting for 10-15 seconds. Pump/prime fuel filter would get it to restart. Changed fuel filter, problem went away for 3 weeeks, til last two mornings, the frost hit and problem returned. Starts for 10-15 seconds and stalls. Now the pump/priming will get it to restart but only for another 10-15 seconds and stall again. Less than 1000 miles on this filter, the new Raco fuel filter. Eventually engine will stay running after the engine temp reaches somewhere around 90-100 degrees according to Edge monitor and 7-10 pump/priming sessions. Some air bubbles out of top of filter cap on an electrical input to cap, not sure what it is.

New to the forum, looking for some help. Ideals are air leak in fuel line somewhere, hope its not an injector issue read so much about, what is this additional fuel filter issue I've read about? Seems to happen in the colder mornings, if you consider Central Calif cold. Does not happen again all day long until the next morning after setting for 8-10 hours. Any help is appriciated.

Welcome to the board!

A leaking 0-ring on the fuel filter is the most common cause of an air leak. I suggest dropping the filter, then use a smear of chassis grease on the o-rings to hold them in place. Be careful, and make sure the o-rings remain in-place during re-assembly. Pull the passenger side battery or the inner fender liner so you can get a good look at how it goes back together.

Jim

[cdgibby]

Thanks for the ideals, I will try to dig alittle deeper this weekend. This morning at 42 degrees it starts and does not stall. Is there something magic about below freezing other than the obvious freeezing. It is suppose to get below freezing again tonight so I assume I'll have to pump/prime tomorrow morning to get it to stay running. Trying to find something I can blame it on instead of starting to replace parts without confirmation that it is the problem.

Thanks again

[DmaxMaverick]

As the temperature drops, fuel viscosity increases (becomes thicker), and thermal contraction is greater as the fuel in the tank cools. Any additional suction on the system (like pulling thicker fuel, or against a greater vacuum) will exploit any weakness in the system. If you have a very small leak that isn't much of an issue when it's warm, getting colder only makes the situation worse.

You might try loosening the fuel cap when you park for the night (before the truck starts to cool off). This might help by minimizing the vacuum in the tank from fuel/air contraction, and park with the grill downhill, if that's an option. A fuel cap with a stuck vent will also cause issues (It happens, but they're cheap....just replace it).