911 HELP

TruthSeaker79

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May 18, 2024
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Ok where do I start…I started with a bad #7 Injector; where I busted the FPR Sensor, Replaced that…drove fine for 2 months, then started throwing a P0087…Service Bulletin about Collapsing Fuel Lines; Replaced all the FEED LINES with the Parker Hose recommended…STILL THROWING P0087…Replaced the Filter Housing…STILL HAVE P0087
*NOTE:
The Manual Prime is completely SUCKED DOWN!!
I drive about a mile, FINE, then I get “Change Fuel Filter” then IMMEDIATELY “Check Engine” “Reduced Power”—-then it STALLS!!

I get out, pop the Bleeder on the Filter Housing—and—HISSS—-UNDER PRESSURE—-PRIME KNOB IS DEFLATED—NO PRIME—

I have to MANUALLY PULL THE PLUNGER UP—EACH TIME to PRIME—-

CLEAR CODE

STORY STARTS ALL OVER!!!

WHAT AM I MISSING?!?!?!?

ALSO: I have an AirDog Raptor 4G 100 being delivered on Tuesday.
 

TruthSeaker79

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May 18, 2024
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My LMM is DELETED and is chipped…but I don’t know crap about the build…I don’t even know how to find out or manipulate the program?!? I am relatively new to Diesels…this is my 3rd. After an 05’ LLY and a ‘16 4Banger Colorado Duramax…but I’m in my rig like a coffin!!! I ANIT PARTIN WITH HER!!!
So Hell or High Water…THIS DOG IS GONNA HUNT!!!
 

TruthSeaker79

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May 18, 2024
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QUESTION:

Are the RETURN FUEL LINES prone to COLLAPSING ALSO??? I guess I assumed the RETURN LINES were on a “PUSH-“ and NOT a “PULL”??

So “COLLAPSING” wouldn’t be an issue, CORRECT?
 

TruthSeaker79

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May 18, 2024
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I guess what “my trouble shooting” has drawn my “conclusion”, is that the system is PULLING AIR somewhere???

COULD RESTRICTION FROM INSIDE THE TANK PLUG THE INLET AND THUS CAUSE THIS MESS?!?!?

(It’s TOTALLY POSSIBLE…junior loaded my tank with ROCKS!!! THATS WHY I ASK?!?? Little turbo loaded my 1yr old John Deere with rocks and I DIDNT CATCH IT…till I HAD TO BUY A NEW MOWER LAST MONTH!!!)
 

darkness

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Jul 15, 2009
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You might need to look at the fuel fill hose. If I recall, the vent runs thru the inside of the hose. If it’s plugged with rocks you will definitely pull the whole system shut. The fuel system runs in a vacuum already.
 

2004LB7

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Dec 15, 2010
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Could also be something plugging the pickup. Most of the supply under the vehicle are aluminum tubing. There are some short sections of rubber hose down by the fuel cooler and to the top of the tank. Also rubber up to the engine

I doubt the return is the issue as it pressurized. The supply is under vacuum. When the CP3 pump sucks fuel, if there is too much suction the primer bulb can get stuck down

Double check you didn't put any lines on backwards to the filter or CP3
 

malibu795

misspeelleerr
Apr 28, 2007
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Either have a collapsed line, or something plugging the pickup in the tank..
I have seen the flexible coupling peal apart inside the hose and plug everything up.
There is 3-4 section of flexible hose on the OEM fuel lines.

If you do decide to replace the fuel line -8 for supply -6 for return. Need about 15' of hose. I did hard tube to AN on the engine and quick connect to AN on the tank side
 

malibu795

misspeelleerr
Apr 28, 2007
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Here's a parts list that I used. IDK what comes in the air dog kit for fuel lines.
8AN to 1/2" QC earl performance 961988
6AN to 3/8 QC earl performance 961965
1/2" hard tube to -8 male
3/8" hard tube to -6 male

Parkers 801 series hose is great, recommend getting some split convoluted tube to go around it for abrasive protection.
I usually use aluminum barb fittings from jegs/summit vs the steel/brass fitting from Parker

With the tube to AN adapters I put light coat of RTV adhesive to fully seal it as you're using SAE fittings on a metric line and it will seep after a while

Hose clamps recommended on the supply side if under pressure though coupling will hold 20-30psi IIRC
 

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Mikey52

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Sep 20, 2018
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If primer bulb is pulled down, too much vacuum in system, either plugged vent, plugged tank line or plugged sock. If the sock has been changed, a gas sock will not work.
 

2004LB7

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If primer bulb is pulled down, too much vacuum in system, either plugged vent, plugged tank line or plugged sock. If the sock has been changed, a gas sock will not work.
Never seen a sock in the Duramax tank. Just a pickup tube in a cup
 

Mikey52

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Sep 20, 2018
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Maybe that far back they didn't have them. Newer ones with in tank pumps do. He might try taking a fuel line and tank cap off and blowing air less than 10 pounds into the line to blow any debris out of the cup.
 
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2004LB7

Well-known member
Dec 15, 2010
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Maybe that far back they didn't have them. Newer ones with in tank pumps do. He might try taking a fuel line and tank cap off and blowing air less than 10 pounds into the line to blow any debris out of the cup.
As far as I can tell, even the L5P doesn't have a sock. But blowing a little air back through the supply couldn't hurt and if something was plugging it up, might dislodge it

L5P in tank lift pump and sender
5763afff33326b904ae2613294e5095e.png
b2d8d20a8e5bb51f45ef63dcb7ff5d7a~01.jpg
 

Nate’s Dmax

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Dec 11, 2020
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Maybe that far back they didn't have them. Newer ones with in tank pumps do. He might try taking a fuel line and tank cap off and blowing air less than 10 pounds into the line to blow any debris out of the cup.
No sock that i know of on any Duramax even the brand new ones. Don’t know that the 2001+ gas trucks have fuel socks either. All have a pick up similar to what posted above.
I guess what “my trouble shooting” has drawn my “conclusion”, is that the system is PULLING AIR somewhere???

COULD RESTRICTION FROM INSIDE THE TANK PLUG THE INLET AND THUS CAUSE THIS MESS?!?!?

(It’s TOTALLY POSSIBLE…junior loaded my tank with ROCKS!!! THATS WHY I ASK?!?? Little turbo loaded my 1yr old John Deere with rocks and I DIDNT CATCH IT…till I HAD TO BUY A NEW MOWER LAST MONTH!!!)
I would make sure the vent is open. Take the fill cap off and see if problem persists. If still sucking it down its time to remove the tank unit and see what it and inside of tank look like.