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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.

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  #191  
Old 06-25-2014, 12:05 PM
TreeFarmMech TreeFarmMech is offline
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Location: United States, Texas, Glidden
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Default scanner

Quote:
Originally Posted by HobbleCreek View Post
What are you guys using to clear this code when you get it?
Any OBD-II scanner with code clearing capabilities (some are only designed to read the code and NOT clear it). I'm not sure how anyone else is performing the action, but I pull off the road, trun off the truck, connect the scanner, turn the key in the on position with the engine off and proceed to operate the scanner. Any parts store can sell you one. You can find them on internet, pretty much anywhere.

I picked up an Innova Model 3120b. It doesn't have the graphing function but I can read the freeze frame with and note some (not all) sensor outputs.

How much you spend is completely up to you.
__________________
1998 Ranger 2.5l, stock, 256k miles and never rebuilt!
1967 Mustang Coupe, 302, T-5, 9-inch, she goes just, having a hard time sticking...
2006 GMC 3500, stock, my current project...
2008 F-350 6.4L - Dead
1996 f-350 7.3, stock, sold at 350k miles

Schaeffer's Lubricants, I was leery, but the added horses and less maintenance are undeniable.
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  #192  
Old 06-25-2014, 02:10 PM
TreeFarmMech TreeFarmMech is offline
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Location: United States, Texas, Glidden
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Default p0087 code THWARTED! and a few other thoughts

An update from my previous post for anyone still working on this.

Did not have an opportunity to run the truck last week, no deliveries came up.

Used all the "old" diesel, installed a new fuel filter, drove around town a bit last week. Delivered a moderate load today, certainly not qualifying as "heavy". Headed to Austin on Hwy 71. 18 miles from the farm (about 60 on the fuel filter) and code thrown. A/C on, Cruise off, tow haul off, just driving normally, trying to keep above 70 mph, 81 degrees out, wind left to right 15-20 mph, moderate incline (nothing near 6%).

Modified my driving habits mid trip. I would accelerate down hill and refrain from depressing the accelerator pedal when headed up hill. Even pulled my foot out of the pedal on some of the steeper inclines.

Got to a section of 71 where there are some traffic signals. Used this opportunity for some full throttle acceleration. Couldn't get a code no matter how hard I mashed the GO! pedal. This is interesting to me. I'm getting up in the rpm range, I'm figuring my injectors are staying open a little longer, turbo is winding up, boost PSI is pretty up there, this motor is giving it everything it has, demanding higher fuel rail PSI. Why no code, especially with the injectors staying open longer dumping more fuel? Sure the CP3 is spinning faster, probably has a pretty good vacuum on the suction line (any hose pinching problems should be pretty obvious).

It got me thinking about it, this code is throwing under 2,000 rpm in high speed and loaded conditions in high gear.

Got to the delivery site without much opportunity for further testing. Oh well. Continued to ponder on the drive home from Austin and took the opportunity to test a little more.

I've narrowed it down to these conditions:
(1) Transmission in drive
(2) Any speed with the transmission in 6th gear (for me 52 mph or higher)
(3) A slight depressing of the go pedal while going up hill (even some not very steep) (pushing it to the floor makes the transmission down shift)
(4) A trailer connected (even an empty one)

With these conditions, this code throws every time.

So I popped it into manual (M on the dash) and selected 6 as my range to see what happens. Couldn't get the code to throw to save my life. I even turned around and went back to the last hill the code popped on. Still couldn't get it to do it.

So for now, I'm driving in Manual.

Further thoughts: Why does this code pop only at highway speeds with slight desired acceleration? Something to do with the transmission and engine communication? Anybody know how many sensors are in an Allison transmission? Why does the transmission, under full throttle acceleration, shift from 4th to 5th at 2700? Why is there a 6-700 rpm drop going to 5th? My foot is still in the pedal, I wanna stay up in the power band, not drop below it. Why, when the code throws, am at 92% (or more) calculated load? Where is this load measured or how is it figured? Why does my truck think it is so loaded with an empty trailer weight of 3,000? Is my transmission causing the increase in resistance? We've religiously maintained the axle bearings on the truck and trailer, they spin very easy by hand.

I'm beginning to think my problem isn't in the fuel system, its in the transmission. Something is telling my fuel system to go to max PSI with a slight depression of the accelerator pedal, WITHOUT down shifting the transmission, allowing more RPMs, boost PSI, etc.

Anyone know anything about an Allison 1000 transmission? I found this video:
http://www.youtube.com/watch?v=8xFwoTCInY8

(According to this video, Allison 1000 gear ratios are 3.10, 1.81, 1.41, 1, .71, .61, hence the big drop from 4th to 5th and the only slight drop from 5th to 6th.)

Do I have a failing torque converter? A faulty pressure sensor in the transmission somewhere? A leaking valve body? Is there anywhere I can plug my scanner into this thing to find out? (No there isn't, unless your trans is post 2009, when "prognostics" was added).

I remember older transmissions had a "dump" valve that was mechanically operated by the opening of the throttle. In higher gears, this valve would cause enough loss of fluid psi to down shift the transmission allowing the torque converter to spin faster and thus re-raise fluid psi while accelerating the vehicle. How is that accomplished these days with all this wiring harness connected to this transmission?
__________________
1998 Ranger 2.5l, stock, 256k miles and never rebuilt!
1967 Mustang Coupe, 302, T-5, 9-inch, she goes just, having a hard time sticking...
2006 GMC 3500, stock, my current project...
2008 F-350 6.4L - Dead
1996 f-350 7.3, stock, sold at 350k miles

Schaeffer's Lubricants, I was leery, but the added horses and less maintenance are undeniable.
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  #193  
Old 06-25-2014, 02:57 PM
Kennedy Kennedy is online now
Long Distance Crew Chief for BMDMAX
 
Join Date: Mar 2000
Location: Loyal WI US
Posts: 10,673
Default Point of clarification

The chemical treatment has not cured your P0087 code correct?

Modified driving habits have helped you skirt around it correct?

I will stick with my original comments that this is fuel supply related:

A lift pump keeps the system under pressure happier and healthier

Secondary filtration keeps the fuel system happier and healthier

Regular use of a quality fuel treatment will often pay for itself with a small bump in economy and keeps the fuel system healthier and happier


Now as to the issue, heavy load high gear low RPM high ambient temps and very high fuel temps are the factors. The return flow is greater than expected due to injector wear. When operated in these conditions, the pump flow is insufficient to maintain demand. I have had some success with manipulation of the pump though ECM programming as IGO1320 has reported. Not 100% surefire, but pretty darn good.
__________________
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!
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  #194  
Old 06-26-2014, 08:25 AM
TreeFarmMech TreeFarmMech is offline
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Location: United States, Texas, Glidden
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Default Trying to out smart my Duramax...

Quote:
Originally Posted by Kennedy View Post
The chemical treatment has not cured your P0087 code correct? It does not appear so. Oh well.

Modified driving habits have helped you skirt around it correct? Yes, but why does operating the truck in manual mode (with 6th gear selected) and driving normally not cause a code? Is the ECM in a different set of parameters for operation or something?

I will stick with my original comments that this is fuel supply related:

A lift pump keeps the system under pressure happier and healthier

Secondary filtration keeps the fuel system happier and healthier

Regular use of a quality fuel treatment will often pay for itself with a small bump in economy and keeps the fuel system healthier and happier


Now as to the issue, heavy load high gear low RPM high ambient temps and very high fuel temps are the factors. The return flow is greater than expected due to injector wear. When operated in these conditions, the pump flow is insufficient to maintain demand. I have had some success with manipulation of the pump though ECM programming as IGO1320 has reported. Not 100% surefire, but pretty darn good.
I'm speaking for myself, but I had Lite Load, high gear, low RPM, moderate ambient temps (it was only 82 degrees yesterday). If a brand new set of injectors is wearing out after 25k miles, either the filter isn't doing its job or the CP3 has gotten weak (or the dealership installed crappy injectors, known to happen...). But others have posted here that replacing the CP3 didn't work either.

I'm not convinced a fuel supply problem, this code should be popping up under hard acceleration (mashed pedal) & loaded conditions if fuel supply was the issue.

Correct me if I'm reading the wrong information but the CP3 is mechanically powered off the cam chain. The only way the ECM can modify fuel pressures is with valve bodies in the CP3 and the FPRV.

What if I have a leaking intake system (think air entering the system AFTER the MAF)? Under high RPMs (more than 2k) vacuum could suck the leak closed, under low RPMs not enough vacuum to pull it closed. Is there an 02 sensor in the exhaust or something reporting exhaust conditions to the ECM? If so, it could be reporting excess 02 (compared to the MAF) and the ECM is trying to compensate by commanding more PSI than the pump is physically able to provide at under 2000 engine RPMs.

I'm still miffed that the transmission doesn't down shift out of 6 with any light/moderate depression of the accelerator pedal, this just doesn't seem normal to me (especially in "Tow/Haul" Mode). If this is truly the case, the transmission can take a lot more torque than the motor can provide (ie, at 65 mph and ~1600 rpm, the transmission is telling the motor "you aren't overloading me, no need to down shift" and the motor is struggling to put out the power to keep the vehicle/trailer going up a moderate incline).

http://www.dieselpowermag.com/featur...a_3500_review/

According to this article, the LBZ outputs 650 ft-lbs at 1,600 rpm. Times .61 (6th gear ratio) = 396.5 ft-lbs of torque at the back of the trans, times 3.73 rear end ratio = 1,478.95 torque @ 8.25" ring gear divided by 3.6 (tire diameter 29.75" divided by ring gear diameter) = 410.82 calculated torque at wheel/pavement contact of a brand new from the factory vehicle. Is that enough for approximately 10,600lb vehicle combo (~6600 vehicle (I have crew cab, "8 ft farm bed" + tool box and 2 20gal tanks) and 4,000 lb empty trailer) at highway speed up a moderate incline? Never mind the the power lost to heat, windage, alternator, a/c system, 150,000+ miles of wear on the engine, etc.

All that said, perhaps I have a clogged up catalytic converter? After 150,000 miles of dirty diesel (approximately calculated 18,750 gallons) causing excess hydrocarbons in my exhaust... Clogged cats can cause higher engine compartment temps. Anybody else noticed that the fuel supply lines are rather close to the drivers side exhaust manifold and the water separator/fuel filter sits right next to the passenger side exhaust manifold? And since the LBZ has EGR cooling, those hotter exhaust temps are flowing through the air cooler, raising temperatures entering the engine compartment. Now we have heat added all over the place due to a clogged CAT. Is this train of thought out of whack?

Has anyone with the catalytic converter delete experiencing the p0087?
__________________
1998 Ranger 2.5l, stock, 256k miles and never rebuilt!
1967 Mustang Coupe, 302, T-5, 9-inch, she goes just, having a hard time sticking...
2006 GMC 3500, stock, my current project...
2008 F-350 6.4L - Dead
1996 f-350 7.3, stock, sold at 350k miles

Schaeffer's Lubricants, I was leery, but the added horses and less maintenance are undeniable.
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  #195  
Old 06-26-2014, 02:19 PM
TreeFarmMech TreeFarmMech is offline
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Join Date: Jun 2014
Location: United States, Texas, Glidden
Posts: 5
Default no sensors after the egr

So crawling around under the truck, I failed to find any sensors after the EGR components. So much for any 02 sensor readings going to the ECM

I also found that the EGR cooler utilizes the engine coolant to cool the exhaust gases, not the air cooler mounted on the front of the vehicle.

So now the cheapest option before me is a deleted catalytic converter. The idea being to prevent the EGR system from cycling higher than normal exhaust temp back into the engine compartment by getting that exhaust out the back of the truck.

I can't help but think that the close proximity of exhaust and fuel components is a contributing factor to this.

Most people posting with this issue use the vehicle for a significant amount of towing. They also seem to not have bunches of mods to their vehicles. Begs the questions:
Why aren't the modded exhaust system guys suffering a p0087 code?
Why aren't the people not towing anything suffering a p0087 code?
We've figured out the fuel treatment folks aren't having a p0087, go figure, they have cleaner burning fuel dumping less hydrocarbons into their catalytic converter and EGR system is taking the brunt of a clogged up exhaust pipe, its the only other direction for all that hot air to go.

If only GMC would have told me to upgrade the exhaust, use fuel treatment, and block off the EGR when we bought the truck.
__________________
1998 Ranger 2.5l, stock, 256k miles and never rebuilt!
1967 Mustang Coupe, 302, T-5, 9-inch, she goes just, having a hard time sticking...
2006 GMC 3500, stock, my current project...
2008 F-350 6.4L - Dead
1996 f-350 7.3, stock, sold at 350k miles

Schaeffer's Lubricants, I was leery, but the added horses and less maintenance are undeniable.

Last edited by TreeFarmMech; 06-26-2014 at 02:31 PM.
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  #196  
Old 04-04-2015, 01:47 PM
mramsey63 mramsey63 is offline
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Join Date: Apr 2015
Location: East Tennessee
Posts: 1
Default Question

Thanks to all that have added their knowledge on this subject.

I have a 2007 GMC 3500 with 455,000 miles, completely stock and use the truck to deliver campers to all 48 lower states. I have been getting the dreaded 0087 code for the past year. I do have a Bully Dog connected but is not installed, only used to monitor temps and to clear codes.

I have a few questions I'd like to ask.

1 Has anyone found a true solution to this issue?

2 Kennedy I've noticed that it seems you believe it will be the injectors almost 100% of the time, but I have noticed 2 or 3 people have had their injectors replaced and it didn't solve the problem for them. What do you feel is happening to these trucks since they do have new injectors installed?

Thank in advance.
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  #197  
Old 04-06-2015, 02:13 PM
Kennedy Kennedy is online now
Long Distance Crew Chief for BMDMAX
 
Join Date: Mar 2000
Location: Loyal WI US
Posts: 10,673
Default

I can only go by what has worked for me in the cases that I have been directly involved with. Some that have done injectors and still had issues could have been overlooking fundamentals ie supply side restriction/lack of lift pump, or gotten poor quality injectors, or had a weak tired CP3. Hard to say.


It those cases we have successfully handled some with injectors and some with lift pump supply usually accompanied by tuning as well.
__________________
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!
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  #198  
Old 06-08-2015, 10:33 AM
Kennedy Kennedy is online now
Long Distance Crew Chief for BMDMAX
 
Join Date: Mar 2000
Location: Loyal WI US
Posts: 10,673
Default

Just an update:

I have been dealing with 2 different LLY (technically LBZ) medium duty trucks battling P0087.

Truck #1 had a lift pump previously and we went through 2 unsuccessful rounds of tuning to fix his issues. Round 3 of tuning was sent last week.

Truck #2 had no lift pump but added my twin lift pump setup. This reduced his frequency of P0087's by 50% so we moved on to tuning. I based this tuning off what I had done for truck #1 even though I had not yet heard back.


Both owners called me today to report that the problem was solved in this weekend's operation. They both tried to throw what they could at their trucks and they just kept rolling. Truck #2 had a lot of black smoke prior to the tuning also which reportedly cleared up. Will keep in touch with them to monitor progress.
__________________
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!
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  #199  
Old 06-08-2015, 12:17 PM
rowekmr rowekmr is offline
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Default

I have been doing my share of internet researching and besides fuel filter change and lift pump most other people make changes without a lot of evidentiary support. It seems people throw CP3's and injectors without really knowing if they are bad. I did some research on a professional mechanic database that accesses GM's info and it seems that they have a return rate test for the injectors that can at least assure an owner if the injectors are bad before spending 4K replacing them. The test for the CP3 were less precise more of a process of elimination but again I would try that before spending the 2K unless I just wanted to upgrade my components. They also had a test for the FPR on the CP3 but don't know how often they fail and the had a bottle test for the pressure relief valve on the fuel rail (forgot the name).

Since I now have a LBZ with the P0087 code I will do some more research and try to be systematic in replacing and hopefully from the cheaper side up instead of the other way around. One thing I can understand is the collapse hoses, fuel under vacuum (creating air bubbles) can both be cured by lift pump much less CP3 longevity which I believe the other manufacturers use in their diesels. I am surprised GM eliminated that component in their design esp since the previous design (6.5L) had lift pumps too.
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  #200  
Old 06-08-2015, 01:58 PM
Kennedy Kennedy is online now
Long Distance Crew Chief for BMDMAX
 
Join Date: Mar 2000
Location: Loyal WI US
Posts: 10,673
Default

Quote:
Originally Posted by rowekmr View Post
I have been doing my share of internet researching and besides fuel filter change and lift pump most other people make changes without a lot of evidentiary support. It seems people throw CP3's and injectors without really knowing if they are bad. I did some research on a professional mechanic database that accesses GM's info and it seems that they have a return rate test for the injectors that can at least assure an owner if the injectors are bad before spending 4K replacing them. The test for the CP3 were less precise more of a process of elimination but again I would try that before spending the 2K unless I just wanted to upgrade my components. They also had a test for the FPR on the CP3 but don't know how often they fail and the had a bottle test for the pressure relief valve on the fuel rail (forgot the name).

Since I now have a LBZ with the P0087 code I will do some more research and try to be systematic in replacing and hopefully from the cheaper side up instead of the other way around. One thing I can understand is the collapse hoses, fuel under vacuum (creating air bubbles) can both be cured by lift pump much less CP3 longevity which I believe the other manufacturers use in their diesels. I am surprised GM eliminated that component in their design esp since the previous design (6.5L) had lift pumps too.
I wish you luck in finding your issue and will watch for the resolution.

The issue is that the P0087 does not happen at idle, cranking, or low pressures where these tests are performed. It happens at high ambient and fuel temps and under heavy loads which is where the highest pressures are called for.


The 2001 LB7 tends to have chronic fuel pressure codes as well. I've done many hundreds of tunes for these. The DTC is P0093 large fuel leak detected. It seems that once the bug bites these trucks all the parts changing you can do will not cure it. I've been seeing the P0087 fixed with pump and injectors only to come back in much less time. Could be sub standard reman injectors or it could be skeletons remain in the closet. Either way I am hopeful to have a tuning related cure. It is highly likely that I will soon be doing an ECM for a customer who replaced pump and injectors 100k ago and now has the issue returning.
__________________
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!
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