Loses Prime

[Ponderosa JT]

My 02 CC DA has failed to start 3 times in the last month. It starts and dies within 5 sec. I open the hood, push the primer 5-10 times and the truck starts right up and continues to run fine. I took it into the dealer to find the problem. By putting a clear line going into the fuel filter, the tech can see air bubbles coming up the fuel line. He assumes that they are and accumulating to a point that it loses prime and won't start. It has failed to start before and after a fuel filter change. He can't find a leak in the fuel line but wants to replace the fuel line and can't guarantee it will fix the problem. Labor and parts $600. The fuel line to the tank does not fall into the 100K warrantee. Mileage is at 58K and all stock. Since it only happens once every week or so, I hate to spend $600. I'm holding off until it gets worse. The service manager said the air won't hurt the pump. Any ideas? How can I have better confidence before I spend the money? Can the air bubbles be coming from somewhere else (the pick up in the tank)?
Thanks in advance,
Jeff

[More Power]

The fuel filter is the most likely source for air entry into the fuel supply system. If the problem began soon after changing the fuel filter, you could remove the filter and check the two o-ring seals.

Otherwise, you could wrap foam rubber around an air hose, then stuff it into the fuel tank filler. Apply a regulated 5-10 psi air pressure to help you locate a fuel leak anywhere in the fuel lines or fuel filter assembly.

Jim

[Ponderosa JT]

Thanks MP,
I was hoping it was in the filter assembly as that would fall into the 100K warrantee, but since the tech was seeing air bubbles before the filter, they rulled that out. Pressurizing the fuel line makes sense.
Thanks
Jeff

[More Power]

The quick-disconnect fuel supply line connection above the driver's side valve cover could be an airleak source.

Jim

[jbplock]

Jeff,

As MP points out .. Good Idea to check the fuel line quick disconnects. In addition to the QD near the back of the drivers side valve cover, there are two more in the flex hose that connects the fuel tank sender to the steel fuel line above the fuel cooler. The QD’s seal with an o-ring and lock to a raised “bump” on the fuel line with metal tabs inside the fitting. To release the fitting you need a special tool that depresses the tabs (see picture). Be sure to get a tool with a deep collar that reaches the tabs. The first tool I tried was too short but the Lisle tool shown below worked for me. Once you have the fittings off, check the O-ring and the tube surface then apply some silicone grease and reassemble (Parker Super O-lube (http://www.manuf-rubber.com/superolube.htm) is good too) … (I recently checked the tube above the cooler on my 03 and found the end was starting to rust .. When the truck was new I replaced the OE hose with Gates 7/16 fuel line and plumbed in a pre-filter/lift pump (http://community.webshots.com/album/77018086bLHHHC))

Good luck … vacuum leaks can be tough to find … Here’s a few pictures …

http://thumb8.webshots.com/s/thumb1/5/62/38/72256238bjrjGJ_th.jpg
QD fitting (http://community.webshots.com/photo/67970835/1072256238033933568bjrjGJ)
http://thumb8.webshots.com/s/thumb1/5/60/41/72256041LaCXPA_th.jpg
Tank Hose (http://community.webshots.com/photo/67970835/1072256041033933568LaCXPA)
http://thumb8.webshots.com/s/thumb1/5/58/50/72255850UuKWsX_th.jpg
QD Tool (http://community.webshots.com/photo/67970835/1072255850033933568UuKWsX)

:)

[Kennedy]

I believe that much if not all of this air is released as the fuel is heated in the EDU. Adding lift supply pressure eliminates this.

[BILLYDIESEL]

Remove Cap For Fuel Line Disconnect.clean Exess Fuel Out Of
Fitting.prime System Let Sit Over A Period Of 5hrs And Check
Diconnect Fitting For Any Fuel.if Fuel Evident Replace