Is there a way to check if the loss of prime is before or after the filter? When I start it(takes a few more seconds to start than it used to) it will die after 10-30 sec. I can prime it with a lot of bubbles in fuel.
If I drive it and let it sit over night I check prime in the morn and no bubbles come out before I start it. It starts and dies in same 10-30 sec.
I have had the filter housing replaced about a year ago. the filter is not yet ready to change and the filter and WIC are tight.

All stock but EDGE with *** set to 1

You could try pressurizing the tank to 5-7 lbs (run an air hose in the filler neck and use a rag to plug it). Make sure it is at least half full and see if fuel leaks out anywhere.

Did this just start one day out of the blue or was there something done to the fuel system that would cause this? You say it's not time for a filter so did you replace the filter and it eventually lost seal somehow. New fuel housing previous...maybe this one cracked as well. My 2 cents

You could pull the output line off the filter housing and put some air into the tank. If you lose air or hear a leak, then that's your answer.

Sounds like it is loosing it after the filter. I was having prime issues with my truck which ended up just being bad fuel that must have been evaporating or something in the injectors/rails but mine wouldnt start at all. I talked to a friend that used to work at the dealership i did and was the duramax guy and he said that when it was after filter it would do exactly as you described, run for a little then die.

Take your fuel filter off, check the O-ring, then retighten the filter. Mine did the same thing after a filter change even after a day or so of driving it. Once the filter was properly seated...no problems.

RD

Did this just start one day out of the blue or was there something done to the fuel system that would cause this? You say it's not time for a filter so did you replace the filter and it eventually lost seal somehow. New fuel housing previous...maybe this one cracked as well. My 2 cents

It did just come outta the blue. I have about 500 miles until next filter change.

I think the hole might be after the filter but I don't know how to check for the leak. Up to the pump its vacuum is that right?

Thank you for all your guys input on this!!

Have you still got the plastic bleeder screw. Why not change that for a stainless one (several Vendors sell them) and give that a go first. I recently shelled out for a new housing, stainless bleeder screw etc, changed the screw first and hey presto.

Thank you guys for your help and input.

If I pressure the tank would it bubble at the screw? I'm thinking it would. So on to the tank pressurization!

Also check the Water in Fuel Sensor. I have had mine work itself loose a couple of times and caused the same issue you are describing. Do not know why they come loose but the do..Jabs

I have a pin sized hole in the back plate of the FICM. Man what a pain to find! I just hope JB Weld will hold it for awhile. $1000 is hard to come up with in no time.

I am having the no start problem when the truck is hot, dealer just said it was the filter housing, but that was just replaced three weeks ago with one from dmaxwrenchkit.com. I tried pressuring the tank but air comes out of what looks like a breather on the tank it is a black plastic tube with what looks like a one way valve on it do I need to remove the valve and plug it to do the pressure check?

Post what mods are on your truck. If you run an old version of the edge module it might be that. I had the same hard start when warm and it was my edge module. Took it off and all was good.

I am having the no start problem when the truck is hot, dealer just said it was the filter housing, but that was just replaced three weeks ago with one from dmaxwrenchkit.com. I tried pressuring the tank but air comes out of what looks like a breather on the tank it is a black plastic tube with what looks like a one way valve on it do I need to remove the valve and plug it to do the pressure check?

2003 GMC 2500hd completely stock

I am having the no start problem when the truck is hot, dealer just said it was the filter housing, but that was just replaced three weeks ago with one from dmaxwrenchkit.com. I tried pressuring the tank but air comes out of what looks like a breather on the tank it is a black plastic tube with what looks like a one way valve on it do I need to remove the valve and plug it to do the pressure check?

you can take the breather off at the top of the tank. just pinch the halo looking thing and it comes off real easy (or at least mine did) It was easier on mine because I have a body lift, but I think you can still get to it. It is located on the top of the tank in the rear.

If I can help more just let me know

2003 GMC 2500hd completely stock

BTW When I had probs with the filter housing it was no start in the morning and after I got it primed it was good to go for the day. I took it in when it got to the point I would have to prime it during the day.

I have a pin sized hole in the back plate of the FICM. Man what a pain to find! I just hope JB Weld will hold it for awhile. $1000 is hard to come up with in no time.



how were you able to find this? did you see fuel coming out? mine is doing the same thing kind of. starting hard, loping idle, then not starting. can get it to run by hand pumping, but only for 10 to 15 sec.

how were you able to find this? did you see fuel coming out? mine is doing the same thing kind of. starting hard, loping idle, then not starting. can get it to run by hand pumping, but only for 10 to 15 sec.

After I pressurized the tank and followed the lines up I could see fuel dripping on the ground and unbolted the FICM and found the leak on the back. At first I thought the banjo washer was bad but I wiped the back off and could see the leak.

Thank you guys for your help and input.

If I pressure the tank would it bubble at the screw? I'm thinking it would. So on to the tank pressurization!

I see you found your leak. :thumb:

This modified fuel cap may help to pressurize your fuel tank, just be easy on the pressure.
http://www.dieselplace.com/forum/showthread.php?t=185111&highlight=fuel+cap

I see you found your leak. :thumb:

This modified fuel cap may help to pressurize your fuel tank, just be easy on the pressure.
http://www.dieselplace.com/forum/showthread.php?t=185111&highlight=fuel+cap

That is what I used to find it! I got my cap from Auto Zone and used a long rubber valve from Big O.
I don't think I would have found it if I didn't use the cap! This should be in everyones tool box even if they don't have a LOP problem yet!

As I have posted in the past, using vacuum instead of pressure will many times show leaks that will not allow liquid to pass to the outside. Attaching vacuum supply and gauges takes thought at times, but can produce better testing results on stubborn systems. When applying vacuum for testing, always double think about connections and other possible areas that would allow for vacuum dropoff. Careful observation is always needed.

As I have posted in the past, using vacuum instead of pressure will many times show leaks that will not allow liquid to pass to the outside. Attaching vacuum supply and gauges takes thought at times, but can produce better testing results on stubborn systems. When applying vacuum for testing, always double think about connections and other possible areas that would allow for vacuum dropoff. Careful observation is always needed.

I know that is the method used by Diesel Techs but with little $ to spend on equipment to be used once or twice its hard to fork out the $100s for the gauges and pump. The cap I made was $10 and produced the results I needed.

I know that is the method used by Diesel Techs but with little $ to spend on equipment to be used once or twice its hard to fork out the $100s for the gauges and pump. The cap I made was $10 and produced the results I needed.

I agree, I like positive pressure to diagnose if it's a vacuum system. It can be a needle in a hay stack.

I still have a LOP even after a new filter head assy (although I think this is again the culprit), SS screws, multiple new filters, 2 new WIF sensors, 2 new rubber hoses after filter assy, a Kennedy Lift Pump and an attempt at pressurizing the system. I built a homemade cap with Gorilla glue as extra measure around the valve stem and cap hole but it ended up popping out anyways and into the tank :)

Want to check and see if the check valves and O'rings are good in the filter head? Put your thumb over the filter head inlet and pump the hand primer. It should hold a vacuum.