P0087 fuel rail pressure low limp under high loads

[rowekmr]

From my limited driving of mines (200 miles) the code comes on after normal slightly aggressive driving empty (on flat lands) without high temps. Once the code is confirmed (CEL comes on) it has reduced power until I clear the code. When I did search there were those towing heavy in high temps and then there were people like me who are not operating at the upper limit of the drivetrain.

[Kennedy]

From my limited driving of mines (200 miles) the code comes on after normal slightly aggressive driving empty (on flat lands) without high temps. Once the code is confirmed (CEL comes on) it has reduced power until I clear the code. When I did search there were those towing heavy in high temps and then there were people like me who are not operating at the upper limit of the drivetrain.

Some of these can be as simple as a supply side leak or restriction. The black plastic fuel filters are often linked to this.

I have a ton of Tech Tips on my site regarding the P0087, bottle test etc.

[rowekmr]

Thanks I read those helpful tech tips posted on your website.

I have a few new is questions regarding the code.

Which sensor triggers the code or is it triggered by the computer from calculations? If it's a sensor where is it located?

What pressure threshold triggers the code? Is that threshold too conservative or can damage occur at that level?

[Kennedy]

The P0087 is sort of a convoluted mess. I can't really say precisely what sets it off. Partly because I don't know for certain, and partly because it's part of what I'm doing in the tuning.

What I can say is that this is the course of action:

1) Eliminate supply side restriction (lift pump preferably my twin pumps)

2) Keep the fuel cool-clean the cooler out (I've seen guys adding fans to help)

3) Bottle test (need to make sure nothing is escaping the relief valve (if the valve leaks its due to #1 above so fix that too)

Once you are there it's now a matter of change parts or programming or both.

In the past few years of working on this I've had what I'd call "decent" success with programming if the truck is marginal. Some that were really bad have had issues and needed injectors. The recent pair that I did were what I might consider really bad. The normal tuning that I did actually made it worse on one initially. This is mostly due to the fact that I also improve performance which does take more fuel. I'm pretty confident that I have things in good control now.

One thing I am starting to see is cases where a guy replaces injectors and often the CP3. The problem is fixed, but comes back even sooner than the previous time. Much of this is lack of TLC and adding protective measures like lift pump, added filtration, and quality additive, but I think some of it may also be systematic. With the 2001 P0093 being the equivalent error it seems with those trucks once you have the DTC the only way to fix it is through programming. This may prove true for the LBZ and LMM but only time will tell.

[rowekmr]

Coming from owning 2 of the worst reputation diesel engines (2x 6.0L and 6.4L) I am shock to hear how this engine has this one issues (P0087) with so many convoluted solutions. I heard so much that the LBZ is the gold standard duramax but honestly didn't know they had fueling issues until I got one.

Now back to mines I will do exactly what you recommend. You were the only definitive source of info that also provided the science behind it. Other places seem to do exactly what you mention throw a CP3 and/or injectors then wait and see but my pocketbook is too small for that kind of game of chance. Thanks for taking the time to share your vast experience you'll be hearing from me soon for that twin lift pump once I get the body work done!

[Jeff Paxton]

After thinking I had solved my particular variety of limp mode problem with the pressure relief valve "plug", I was wrong. Traveling in this springs higher temps, it was back with a vengeance. On the relatively short trip from Woodstown, NJ to Harrisburg,PA in May, the old truck fell into limp approx a dozen times. Oddly, not full blown 30mph limp, but around 50mph semi-limp. So I guess the plug was doing something, but I knew this truck was not making it back to Colorado.

I've sunk enough $$ into this truck for this and other issues. And after all it had 280k miles so I decided it was time. I traded it in. It will still make some farmer or kid a great daily driver, its just that its days of towing 14k were over. Here's hoping I don't re-visit the issue with the new truck!

[Kennedy]

I've been doing quite a few ECM tunes this season and while I can't work miracles I have made the truck much more useable. I have it to the point where if it does code the check engine light will come and let you know, but will continue to operate normally.

[blackcurse]

Hello, I just finished reading the 21 pages of this thread looking for a fix to this problem. I will give some background on my personal problem I am having with my 06 LBZ with 92,000 miles on it. When the following incident occurred, I already had the 4" down pipe back exhaust w/ no muffler, EGR block off plate, PPE race plug and PPE tuner on level 3, fuel rail pressure, boost and pyrometer gauges. This set up had been in the truck for years with no issues.

Last year 6/6/2015, i was traveling thru Mass. and stopped at a full service fuel station where, the kid pumping, filled my truck with gasoline. It was idling, I have 4" straight exhaust, a green gas cap that says diesel fuel only and I pulled up to the diesel pump. Needless to say, I only made it 3 miles up 495 before my truck died. I had no idea that it was full of gas. I cranked it over to try and start it, it tried to fire and the locked up. Hydro-locked, cylinders full of gas.
It got towed to GM certified Diesel repair shop #1, where they let it sit a week, fuel system full of gasoline, before they worked on it. They drained the fuel system, put some new diesel and an additive in it, changed the filter and said it was fixed. I drove out to Mass. (4 hours from my home) to get it, left the dealership, made it 150 miles down I-495 before my truck died. The only way I could get it to run was by pumping the manual primer, as soon as I quit priming it, it would quit.
Got towed to GM Certified Diesel repair center #2. There they replaced the CP3 and injectors. Called me a week later and said it was done. So again, I drive out to Mass. to get it. This time I make it home, and over the next few months it seems OK. So now its October and we decide to go camping, hook on my 30' camper and head up in the Adirondack Mountains. About an hour into the trip, yep, you guessed it, CEL comes on and the truck is in limp mode. First time this happened, did it 6 times on my 300 mile trip.
Over the winter, I battled with this issue by playing with the tunes, changed all rubber lines, replaced the filter housing, drained and cleaned the tank myself, cleaned the pickup in the tank, put in a PPE fuel rail fitting, took everything off and put the truck back to 100% stock, went back to my mods and nothing fixed the P0087 that pops up when I work my truck. It can be towing a trailer up a hill, hauling gravel in the bed, or just doing 4th gear brakestands, whenever i am hard on the throttle for extended periods of time, it will go in to limp mode and kick a P0087.
This spring I had to tow my camper to a motocross race, and drove 350 miles to and from the track in limp mode, and I continued to fight with the truck, but now it seems it will limp more easily. Used to be I had to really get on it to cause it to limp, but now I can be just driving the truck empty and if I go WOT long enough to pass a car or something, Voila, CEL comes on and P0087 is thrown. It now seems to be getting worse.
So I take it to GM Certified Diesel repair shop #3. They hook the gauges on to check low pressure supply rates and determine its a dirty fuel and air filter. Call me, say it's fixed. I go and get it and on my way home, I beat on it, and at about 125 mph, CEL come on and its in limp mode. Every time it goes it limp mode, at WOT my fuel rail pressure gauge goes from 26k at the initial throttle hit and fades down to 4-5k. Sometimes the truck shifts, and it goes back to 26k, sometimes it flashes up to 20k and bleeds back down to 4-5k then limp mode occurs.
I turned around and limped it back to the dealership, where try #4, they replace the CP3 again. I get it back, and limp mode again not 5 minutes after I picked it up. They want it back now to try replacing the ECM. I have had GM Customer Service involved now sing April of this year, and as of now,and they cannot figure it out. To sum it up, everything in the fuel system has been replaced, and now somethings twice. Any ideas on this one, truck was awesome before it got gasoline in the system. Its time to look elsewhere for the problem, so now they want to try replacing the ECM. I am going to suggest the fuel rail pressure sensor, sounds obvious to me, but what do I know. The truck all stock now except the exhaust and I can limp it by just hammering the throttle and not letting off until it does limp, generally by 85-90mph my fuel rail pressure gauge is dropping off and the CEL pops on.
Sorry for the lengthy post, but I have over a year trying to figure this out.

[weekendhauler]

Did you change the ECM? I have a 2008 2500 Duramax, I purchased in 2009, I have towed the same 5th wheel every summer. This July I was driving on I 70 in Denver and it went limp. It was 95 outside temp and engine was 210. It went limp 10 times at 55 to 70 MPH, up hill and down, in the next 90 minutes. The next two days it would go limp no less that 20 times on the road to Los Angeles. Dumped the 5th wheel and drove in LA traffic for 5 days in temps over 100, with no issues. Took the I 40 home and the truck went limp even when the temps we in the 80's or above. Hooked up the code reader and cleared the code when driving which takes about 30 sec, dropping 15 MPH but I did not have to stop. Just pressing the link button when you get the engine reduced power light, p0087 appears then hit clear code, the vehicle will maintain speed and in about 20 sec. full power is restored.

Reading all the past logs on this page and other pages, I was thinking the turbo is working big time pulling the 5th wheel and making heat and I wondered if the ECM was over heating and tossing the code. I do not buy the fuel temp because I cleared the code and kept driving and vapor lock would not clear that fast.

I was trying to think of a way to cool the ECM and take a day trip to see if it still tripped a code.

[Kennedy]

I have updated my Tech Tip:

http://www.kennedydiesel.com/docs/Du...ure%20code.pdf


Since my June revisions I have had zero reports of reduced power. Depending how bad the injectors are some still report a P0087, but all are able to drive right through it.

[Mark Rinker]

Great news. Interesting to see the # of hits on this thread, after almost seven years...never seen any problem resist a 'root cause resolution' quite like the "P00087 Low Fuel Rail Pressure" gremlin...

[Kennedy]

Root cause: excessive return flow from the injectors due to wear.

Cheap fix: Kennedy Custom ECM programming

Expensive fix: 8 new injectors

[a5150nut]

Root cause: excessive return flow from the injectors due to wear.

Cheap fix: Kennedy Custom ECM programming

Expensive fix: 8 new injectors

Or do both and be good for a lot longer!

[Mark Rinker]

Root cause: excessive return flow from the injectors due to wear.

Cheap fix: Kennedy Custom ECM programming

Expensive fix: 8 new injectors

Where does "Lift Pump" fall into that continuum?

JK with all respect due, anyone that takes the time to re-read this nearly seven year long thread would deduce that it certainly WAS a long and winding road finally leading to 'root cause'. I'm glad that you stuck by your customers and finally found a programmatic solution for this problem! Congrats.

Glad its solved. Hope GM has/will incorporate better ECM programming in the future to allow for a wider range of injector return rates as the injectors wear over time.

[Kennedy]

Where does "Lift Pump" fall into that continuum?

Mandatory for any Duramax in my opinion and experience.

[Mark Rinker]

Mandatory for any Duramax in my opinion and experience.

Your opinion is welcomed, your experience is deep and wide. Please explain

• Why GM has sold millions of units since 2001 without a lift pump;
• What is the accelerated outcome of not having a lift pump - i.e. premature CP3 pump failure, premature injector failure, global warming, etc;
• Why it took seven years to arrive at a programmatic solution for the P0087 error code, if adding a lift pump was not the solution.

Curious, as I've been since 2009 when I first started this thread.

[Kennedy]

http://www.kennedydiesel.com/docs/Du...ift%20pump.pdf

[Sirgrinalot81]

New to the diesel life and having some issues. I have an 2009 lmm 95000 miles keeps throwing p0087 and is going through fuel filters like 1 a month. Totally stock. Also have a lot of water in the fuel. Located in Kansas. I just ran it almost empty put seafoam in it and filled it up. Think I got a bad tank of fuel from caseys. Before it was throwing p0088 instead of the p0087. Any help is appreciated thanks

[Kennedy]

New to the diesel life and having some issues. I have an 2009 lmm 95000 miles keeps throwing p0087 and is going through fuel filters like 1 a month. Totally stock. Also have a lot of water in the fuel. Located in Kansas. I just ran it almost empty put seafoam in it and filled it up. Think I got a bad tank of fuel from caseys. Before it was throwing p0088 instead of the p0087. Any help is appreciated thanks

What I would recommend is a small bottle of FPPF Fuel Power to dry things up in your tank and then find a better fuel vendor or who spiked your tank.

From there my Tech Tips have the answers. On a daily basis I am "fixing" this with my pumps and tuning and will add that I am now hearing from a lot of "second round" guys who did the injectors and repeated shortly after or even immediately. The solution is still the same, still highly effective, and to me it just makes sense to do something that improves the system rather than just replacing parts with same.

P.S. I would NOT get hung up on water separators as many seem to be doing. You are one of the very few that has ever found any water in their systems

[CoyleJR]

I just returned home from four months on the road pulling our 38' 5th wheel. The truck and 5th wheel have a combined weight of 23,800 lbs and the temperature was often well over 100 degrees. My truck is a 2006 LBZ with 240,000 miles and this is the first time it has shown P0087 code. I found that if my fuel tank level was below half a tank, the temperature was over 100 and the truck was working hard pulling a steep grade it will throw P0087 code. I was able to repeat this problem code several times and fix it by opening the valve on my second fuel tank and adding fuel to the primary truck fuel tank. For 240k miles I have always kept the truck tank full by gravity feed from the secondary tank. This trip was the first time I let it get below half a tank of fuel. A full fuel tank must cool the hot fuel returning from the motor and that cool fuel keeps the truck from showing the P0087 code. I realize that there can be several causes for a P0087 code to show up but on my truck high fuel temperature seems to be the cause.

Additionally, I keep the small fuel cooler radiator in front of the fuel tank very clean and I am now considering installing a second fuel cooler on the right side of the truck.