The Diesel Page Forums

2020 - TDP's 24th Anniversary
What's New | Feature Articles | Product Reviews | Member's Area | Free Forum Registration
Duramax 6600 Diesel Page | Advertiser's Section | Classified Ads | The Diesel Page - Publications

Go Back Forums > 2001 - Current Chevrolet & GMC 2500HD/3500 Light Trucks > Duramax 6600

Duramax 6600 Welcome to the Internet's first Duramax 6600 diesel discussion forum for the LB7, LLY, LBZ, LMM, LML, LGH & L5P RPO code engines. Tips on performance, fuel economy, troubleshooting and more.

Thread Tools Display Modes
Old 02-04-2019, 07:52 PM
beleive beleive is offline
Join Date: Feb 2019
Location: El Dorado Springs
Posts: 1
Default no run, done simple stuff

went out one morning and truck would not start. When I came home for work I checked easy stuff like fuel, oil.
With no luck I ran a scan on the truck. I dont remember the codes but do remember that it pointed to the FICM. I check for bad wires and connections. All looked good there. So, I bought a new FICM. I installed it thinking my problems would be solved. So Went to fire turck up. WOE be Hold the truck would not run. I went back and bled and primed system again and again. Still same results.

The truck will start for about 4 seconds but wont stay running. Only if I prime it by hand again will it hit but wont stay running. 3-4 seconds. Ive tried to keep it running by pumping the primer but only last for about 10 seconds. I had someone rebuild my filter head (I was busy with work). Reinstalled with same results. No codes are showing up after replacing the FICM. I did check wire harnesses looking for anything with no luck.

Is there anybody willing to walk me thru diagnosing this truck. I dont have the money to pay someone. Im in the middle of nowhere. All shops I walk into say they would if it was a powerstroke but refuse to sork on duramax.

The truck is a later model 2004 3500 dually 4x4 has 160000. Tomorrow Im going to try and figure out if the inj. pump is pulling vacuum. Whle Im climbing around Im gonna try and replace rubber line. hope someone here help. Thanks.
Reply With Quote
Old 02-05-2019, 06:12 AM
DmaxMaverick's Avatar
DmaxMaverick DmaxMaverick is offline
Join Date: Apr 2001
Location: CA
Posts: 12,617

Welcome aboard!

I think you're on the right track, chasing the bubbles. If it runs and dies after priming, and runs longer when you pump the primer, it's likely you've identified a problem. A couple simple things come to mind: fuel filler cap and fuel filter. Wild temperature swings will exaggerate fuel expansion and contraction in the system, and will exploit any weakness.

The Diesel fuel filler cap vents in both directions, and they fail over time. They are cheap, and should be replaced early in the diagnostic process. A failed cap vent can cause loss of prime as the fuel system volume contracts, usually during an overnight sit, and is exaggerated as the temperature drops from operating to very cold. You can leave it loose to mitigate any effects in the meanwhile.

The fuel filter may have lost it's seal, and is usually easily restored by a removal and reinstall (often just a loosen-tighten). If you're using the plastic can model filter, all bets are off. Good luck with that one. I suggest replacing it with the steel can model, at least during this process. In most cases, the plastic filter does not cause issues, but can be problematic with some. Just a bad idea that adds potential point of failure, IMO.

Adding a fuel lift pump and controller system will do 2 things. One is, it will absolutely prevent air intrusion while it's running. The other is, it will help identify fuel system leaks between the lift pump and engine-driven high pressure pump. While it is recommended, the OEM system should not prevent running though, in any case, if the system is otherwise healthy.

Do this to identify air intrusion (even if you've already done it):
Open the fuel filter bleed screw on top of the fuel filter assy, and pump the primer until fuel is present. Close the bleeder screw. Pump the primer until you can't. This will push fuel through the high pressure pump. It may take 30-50+ pump cycles, so just keep going until it's very hard to push. Start. If there are no significant fuel system leaks, the engine should remain running. If it starts, then dies, repeat the bleed process. If you bleed air during this, the problem is not the high pressure pump. You'll need to identify the air leak source.

This may not be the end of your issues, but it must be eliminated early if you have any chance of success. Let us know where this gets you.
1985 Blazer 6.2
2001 GMC 2500HD D/A
2014 Chevy Cruze Diesel - Fabulous car, no problems at all, but sold Nov. 2016 @ 55K miles.
Reply With Quote
Old 02-05-2019, 06:34 AM
DmaxMaverick's Avatar
DmaxMaverick DmaxMaverick is offline
Join Date: Apr 2001
Location: CA
Posts: 12,617

Also, while you have the plastic fuel filter bleeder screw off, inspect it very carefully for cracks and/or damaged O-ring. If any, you're dead in the water until replaced. I recommend a quality aluminum or (stainless) steel model. A bleeder T-valve can be installed at this time, if desired (recommended - makes bleeding a lot less messy).
1985 Blazer 6.2
2001 GMC 2500HD D/A
2014 Chevy Cruze Diesel - Fabulous car, no problems at all, but sold Nov. 2016 @ 55K miles.
Reply With Quote
Old 02-05-2019, 07:31 AM
Kennedy Kennedy is offline
Long Distance Crew Chief for BMDMAX
Join Date: Mar 2000
Location: Loyal WI US
Posts: 10,760

Building off the leaky fuel filter especially if it is the black plastic Wix/NAPA version. Also check for rusted out lined down below.

As for the CP3 they seldom fail, but I definitely have seen the transfer side fail and not produce vacuum.

Also where is El Dorado springs and how cold is it there? With the recent cold snap it was tough to keep fuel liquid.
Kennedy Diesel-owner
More than just a salesman-I use and test the products that I sell on a daily basis!
Superflow Lie Detector in house
2002 Chev K2500HD D/A CC Long LT 11.77@ 124mph at 7700# fuel only-e.t. needs help
2005 Chev K3500SRW D/A CC Long LT(SOLD)
2007 Chev K2500 Classic EC Short LT (Sold)
2012 GMC K3500SRW D/A CC Long LTZ Happy Birthday to me! Built 1 working day after my birthday and delivered 7 days later.
2016 GMC K3500SRW D/A CC short LTZ

Custom tuning in house using EFI Live tuning software!
Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -7. The time now is 11:53 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Copyright 1996-2020 by - All Rights Reserved