Dude, after 10 plus years losing prime and no one had a solution, I sent this video to my mechanic and problem solved. Thanks so much

Really really appreciate guys like you that take the time to provide GRAET information. Thank you.

I am just embarking on the same problem thank you for pointing me in the right direction I will let you know how this goes❤

Really good advice for the people want to fixed self truck problems thanks for the advice and help with the duramax trucks

Man these back to back videos. This is awesome

Great video, have the exact same problem on my 06 LBZ. Figured it was a tiny air leak, but I hadn't no idea what I'm looking at with that mess of wiring and lines. This helped a ton for where I should be looking and for what. I figured it would be a bigger leak than that. I probably wouldn't of even took a 2nd look at that hose.

This is the video I’ve been looking for! Thank you for the explanation at the end. My truck has been unable to smog for a month now due to P0101! I’ve already cleaned my filter and EGR, but noticed a second code now related to fuel pressure (p1093). From what I’m reading, this could be caused by a leak similar to this. Wish my luck on hunting it down. Thanks again.

this just worked for me first time working on a duramax

Nice fix, I have an 06 Duramax 3500 that starts and stops right away after sitting. I'll give this a look.

Nice ass durmax. You keep that baby clean. Good job finding the leak

My 2004 LLY has this problem on very hot days, definitely going to look into this. Thanks for the video.

Finally!!! I'm having the exact same issue on my 04. I had s feeling it was might be a hose, but i haven't ben able to find it. I'm foing to check that hose.

My 2005 LLY is doing the same exact thing. My hoses look a little suspect but I didn’t think they were bad enough to cause this. I will be doing what you did today in hopes it will work. Thank you for the video. Top shelf! Will report back😢

Good video, I had a full set of fuel hoses sitting in the garage I ordered last year thinking they were going to need replacement from the looks of them. Had my first air pocket/no start today on my 2002. I'll be replacing them tomorrow.

Thank you for your time! Great explanation!

I have the same problem on my truck, tomorrow I prove to repair the leak and check if all works good, thanks a lot man, and nice truck! best regards from switzerland!

GREAT video sir. thanks

GREAT video!! Im having that problem now!!

Great work thank you!

Commenting on the video for the algorithm is

priming pump on top of filter housing . fixed mine and my sons truck .

Awesome video, thank you sir. Having the same problem with my 04 3500. Ran fine yesterday after fuel filter change will not start now?

Excellent excellent 🎉🎉🎉❤❤❤. Huge help bud thanks!

My problem was the steel line coming out of the aluminum filter head. It was loose and allowing air to suck in instead of fuel. I removed the line by twisting and pulling. Cleaned it and JB welded it back in. Problem solved.

Mine was the filter housing...Replaced all the seals...The bad o ring was for the filter heater connection...

The fuel sender unit have a filter, changing it will solve many no start problems.

I like your design so that was cool. Now the fuel has to be filtered before it gets to the fuel rails and injectors. I want to see that diagram because I’m not seeing where the fuel gos into the engine. I assume but not sure that lines come off the CP3 and go to the fuel rails/injectors. Also what I learned here is that think is that the fuel is filtered before it even gets to the CP3

My 2002 was doing the same thing and it was actually the FICM leaking from the back epoxy sealant.

Good video

Mine prime is same.. soft... YOUR good

I assumed the primer bulb would act as an anti backflow valve, but it sounds like that is not the case? My truck started ticking really bad out of the blue on startup one morning, like it had an instant injector failure. we shut it down and just started it a couple times to show a mechanic the sound, he agreed it sounded like injector failure. My plan was to pull the injector connectors off until we isolated the specific injector issue. Before we were able to, it started doing what yours did. We would have to prime it, it would load a slug of fuel then die within 2 or 3 seconds of running. If we pumped the primer it would go soft completely after about 10 seconds. I bought a whole new filter housing, that did not repair the issue. Does it sound like the injector could be bypassing so much that it would do that? Feels like I hit 2 different problems at the exact same time, now I don’t know how to diagnose either. I would hate to spend thousands on injectors and find it was a $5 tube causing everything.

I have a 2007 that sat through a cold snap and now will not start. No/low pressure to the schrader valve bleeder. Priming pump was mushy as well. I am guessing air in the system?

My 2003 is not holding prime at all it won't start or run unless it is ether, and after hand priming it 10 minutes later, no fuel pressure. Could this be the same issue?

I have an 08 Chevy Duramax put a new prime housing filter housing on truck still won’t start but if we push on the prime button it will start as it’s cranking do you have any ideas and when you shut it off and go to start it Again it won’t start until you push the button one time or twice

BEST VIDEO EVER!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

So correct me if i'm wrong.... The leak was After the filter/primer assembly, but before the injection pump (cp3)?

Hey my 07 duramax, 2500hd. Found the suction line on drivers side 3/8” metal tube rubbed through rubbing against something 2 ft down from QD, GM flaw, many things rub and where on this model, even top radiator hoses and even the large wire QD hitting the cooler tube.

2013 chevy hd3500 6.6 losing prime replaced hose to Schrader valve but it ran but cut off

Same truck but when pumping primer Ik not geting any fuel to it. Tanks full any guesses ??

Mine is dry through out the truck, primer goes soft right away. Starts right up with starting fluid, and runs just fine. Could I have a leaking fuel injectors?

Good video, thanks for the the info. Question for you... My 03 LB7 threw a p0238 code for boost sensor so I replaced the MAP, I also recently replaced the TPS and the Baro sensor trying to chase down a p2227 code. Now it cranks but no start. Both batteries are brand new.... Any thoughts? Fuel system seems to be good, wires and fuses seem to be good.

If you ran a smoke machine through the fuel line near the tank, do you think that smoke would have come out of that leak? I'm having a similar problem but after replacing the CP3, the FRPS, the fuel filter housing, and the hoses coming off the fuel filter housing I still get VERY low ACT fuel rail pressure on crank. Like 7 of 38 desired (on live data) no codes and if I give her a little ether bump, she will start and run perfectly. Shut her off and attempt to restart her and she will only crank no start.

Mine too... Fuel in the tank. Tank line is good. Primer is holding pressure. Must be this?? Also.. mine will choak n gag on occasion... For no reason.. just driving along. Doesn't seem to matter how much fuel is in it... Or the speed. Thoughts? Gotta be a pin hole?

Where can I find a diagram or a video on all the fuel lines on this truck?

Good video for sure but the small tubing you replaced doesn’t have pressure on it with the truck not running right? Correct me please but I thought the CP3 was gear driven and would only build pressure when cranking and running. Teach me something

Same exact issue with my 04.5 lly. I got a fass on it that sounds like shit so I’m wondering if that’s what it is. But it’s got a fuel pressure gauge and it shows 0 until I prime it up before starting

Hi my truck a 2003 duramax started having a long crank issue, but would start. I found that the fuel filter head was leaking a little fuel so I bought a rebuild kit for it and now it will just crank no start. I did the 15 second crank test to see how much fuel was returning and it was well under 100 ml. I also hooked up a scanner and it doesn't have enough pressure to start the truck. I am thinking failed cp3, but do they just fail like that? I had no other indication of fuel pressure surging at idle before hand. I also blead the system multiple times. I also replaced all the fuel lines from the tank and return lines with nylon lines. Also replaced the fuel cooler. Just wondering if you have any other information that I might be able to try. Thanks

My 02 lb7 got a lil water in the ficm from the plug not being when radiator hose busted is what I’m guessing now the truck runs horrible loses prime and is putting oil in the coolant reservoir and diesel in the oil and is in limp mode take a good minute to start pretty much new injectors any guesses anything helps

My lb7 losses prime when its cold over the span of a few hours. One day, when it was exceptionally cold, i lost prime while driving twice. After dealing with this problem for a while the truck threw a p0088 code, and idiled very poorly, made it home (fuel pressure too high) and now wont start. Replaced filter and FPR, still no start

Would this cause truck to idle rough and surge? My LLY is loosing prime over night

I changed every damn hose there is. New fuel filter head, injectors are new, cp3 is new. I added an inline lift pump for more fuel pressure and I am still getting a no start. My primer is rock hard all the time. Even when I didn’t have the lift pump it still stayed primed. Maybe this is a main fuel line issue? Any help would be amazing.

Lb7 turns on at cold start but when the truck is hot it will crank till the batteries die. But if I spray some starter fluid it starts

04 lb7 brakes lock up while driving im limited to like 15miles all 4 wheels lock up, brake pedal hard as a brick at which point then i have to releave the pressure on brakes. 4 new calipers. Builds pressure while driving any ideas ?

I have a similar problem, extended crank and starts and dies sometimes. But if the tank is over 1/2 full it starts right up. It gets very bad under a 1/4 tank. I’ve been told it’s probably still an air leak like this but it’s hard to believe the truck runs and acts perfectly when you fill it up

Installed XDP Duramax Cat adapter fuel filter on 2016 gmc Duramax. Per instructions. Bled fuel system. Truck won’t start.

Could that cause a build up of air over time driving and cause stunbling?

My truck has the cat fuel filter on it. Never had this issue till the last time I spun a filter on now only if the truck is facing down hill it gets air locked

Have the same problem with my lb7 but it dies when it’s hot outside and the ac on but when it’s cold outside it won’t do it. If it like 90 degrees out it will do it sometimes when I’m driving. Not sure any help would be appreciated

So what would be my problem if my fuel filter drains but won't start ....reprime .....same thing. But I can start it with starting fluid and it will stay running

So is it all 1/2" fule line for all the rubber line ???? Thanks

2010 LMM, when my truck is between 1/2 and 1/4 it wont turn over (after sitting a hour or so) when the lift pump (FASS 150) is on, if i unplug the FASS and prime it manually it will run just fine until empty. Any ideas?

My 08 sounds like this

I have a 2002 lb7 214k miles zero blow by Last friday i drove the truck to work 11/3 it drove and felt fine i shut the truck off and worked a 12hr day came out and it cranks but no starts. It seems like its not getting fuel if i crank it for 10-15seconds then look out the pipe theirs zero raw fuel coming out. Has a code for glow plug circuit a and intake air heater but im in phoenix ambient temp is 60-85 degrees It wont even start with a squirt of ether. A buddy of mine thinks the cp3 died a slow death, due to me driving with a filter head loosing prime”aerating the fuel while driving” he advised me to put a lift pump which i did and got a week out of the truck before it died i pulled the fpr and lines on cp3 checked for metal shavings to see if it grenaded the pump zero metal shavings. One time when i plugged in a snap on solus scanner it said something about U1800 failure to communicate with ficm i cleared the code cranked it several more times code went away for that. Kinda lost at this point on where to further diagnosis it. Dont want to order the cp3 and do the job for it to still CRANK NO START PLEASE HELP I replaced the filter head and the glow plug module prior to my buddy telling me to pull the fpr and look in the pump for shavings.

1:56 if you can already see fuel around your brass screw that should be plastic, thats a leak. the plastic will self seal when tight. brass wont. anyway if this has a leak, you lose prime also

I got a 2004 lb7 duramax, I went to fire it up to head to work started it fired up normal then as I was backing up it died so I tried to prime it and got nothing I primed it for ever and still couldn’t get a prime what could it be?

My lbz just started loosing prime cant find rhe problem anywhere replaced the fuel filter with housing the sensor on the filter is not leaking. Replaced both lines going to the fuel filter housing. Cant see any leaks anywhere from the tank all the way to the fuel injectors its driving me nuts

My LB7 died suddenly under the hood on passenger side had been spayed with fuel looked like . Changed fuel filter it started ran 10min then died suddenly pumped filter was nearly full want start I can't find a leak anywhere? Help please

Do you know anyone who can tune a LB7 that has HP tuners all ready installed in Los Angeles area?

Would this cause a complete no start condition?

3 months in and still holding pressure !

My LB7 is losing prime when hot and generally when the fuel tank is under 1/2 tank. On rare occasions it will die while at a red light. It generally happens after I stop somewhere and come back out to start it and it won’t start. I have to manually prime it to get it to start. Sometimes it takes two or three times to get it started and remain running. Recently, and again it is occasionally when it won’t start when cold. Again I have to prime it manually. Any ideas?

Add a air dog lift pump

My wife has a problem in which her car is complaining about a timing belt.. maybe you can take a look.

Those clamps are too big.

Glad I don’t own a dirty mac