P0087 fuel rail pressure low limp under high loads

[WhiteTruck]

While rare, there is one potential area that can cause a restriction and yet not be detected by checking at the factory test port. There is a short section of line/hose that is AFTER the test port going to the injection pump. The rubber part could deteriorate internally, causing a restriction. I wouldn’t look at this until the usual causes of low rail pressure have been checked, but something to keep in mind.

[Clintv331]

For the past few weeks my truck (2006 LBZ) has been taking longer than normal time to start and has gotten worse in the past two days. Well two days ago under normal driving conditions (no load or anything) I get DTC P0087. Once the engine light was on i couldn't rev up more than 2k rpm (in park or while driving). i cleared the code with my tuner and not two seconds later it was back. at first i was thinking it was my fuel filter since it was about time to change it. Well i changed the fuel filter today and then went for a test run. I first cleared the code before taking off. once i got to not even half throttle the dtc was back. it feels like it's not getting enough fuel and is being restricted. when i got back i turned the truck off and when i started it back up it didn't take as long as it did before i changed the filter. also there is a little bit of black smoke coming out the exhaust when at idle. I have it on stock tune.

Could this be due to those hoses collapsing, bad injectors, bad fuel, or what? Can someone please give me some insight on this.

Performance mods: K&N Cold air intake, MBRP 4" turbo back exhaust, & Bullydog PMT

Thanks,
Clint

[Kennedy]

As stated earlier:

There is a simple, sure fire way to test all but the one point of restriction that White Truck mentioned. It also will save you from making premature filter changes and let you know if indeed the filter is loaded:

[Kennedy]

Also watch your WIF sensors. Been seeing some of them start to leak. When an extended crank is noticed I generally recommend pumping up the primer bulb hard and this will often show a leak.

A lift pump would keep the system full of fuel and not air...

[WhiteTruck]

The information in GM PIP4526 is only helpful in the sense that it says that GM approves replacing only the hose portion of the line instead of the complete line(s) they recommended in the past. There is no new diagnostic information in it, as the supply line diagnostic is still done with a restriction gauge as JK recommends for possible causes of P0087, P0093 or P1093.

[Demilee]

Has anyone found a resolution to this problem? We are having the EXACT SAME problem. We've already replaced the hose recommended in GM PIP4526. We had that done in Austin, TX. We thought it worked until we got into some hills in Arizona and California on our drive out there.

We'd rather not spend the $4k+ on fuel injectors if that isn't the problem. Of course we have 117k miles on our 2008 3500 DRW Silverado so a warranty claim is out of the question. We only found out about the issue right after we bought the truck at 105k miles to tow our 2012 Voltage.

Any help would be appreciated!

[Mark Rinker]

I do not know of any solution to this GM programming error, other than (uneccesary) injector replacement.

Have started seeing the same issue with my 2009, starting at 125K miles. In all other ways the truck runs and performs as new.

For the $4500 injectors cost, I'll keep pushing the 'reset' button on my scan tool and clearing codes until someone programatically fixes this bug in the ECM code. When under these conditions, I keep it plugged in and resting on the passenger seat. Silly, huh? I reset the code at least ten times yesterday.

GM should be more interested, as it causes a liability issue when you reduce power to someone towing heavy on a hot day uphill...NOT good.

[greatwhite]

...
For the $4500 injectors cost, I'll keep pushing the 'reset' button on my scan tool and clearing codes until someone programatically fixes this bug in the ECM code. When under these conditions, I keep it plugged in and resting on the passenger seat. Silly, huh? I reset the code at least ten times yesterday...

You just brought back memories of driving down the road with a glitching PMD and the laptop set up on "clear codes" to stay out of limp mode....

Yeesh.

[More Power]

These rail pressure code problems come up occasionally during the hotter summer months in trucks with some miles on them - like 75,000 to 150,000 miles, while the injector data (balance rates, etc.) looks just fine when sitting in the dealer's parking lot.

The Bosch high-pressure pump appears to have a more difficult time producing the commanded rail pressure when temps are high and the fuel has thinned due to the high temperatures. Not able to meet the commanded pressure could be due to excessive fuel return flow in the injectors, pumping plungers in the Bosch CP pump not able to produce the pressure or a heat-related problem with the fuel rail pressure sensor.

With higher heat, the close fitting parts within the injectors and pumps can't generate the pressure it needs to. One way to mitigate this problem is to do something to keep fuel temperature down.

Is the return fuel cooler, located ahead of the fuel tank, clean? You can also maintain a higher level of fuel in the tank. More fuel in the tank provides a larger heat soaking reservoir. Worst case scenario - a low fuel tank and a mud caked cooler, then tow heavy in high heat. Is a larger fuel cooler or an auxiliary fuel tank (to keep the main tank full, longer) workable ideas... instead of replacing a set of out-of-warranty injectors?

If this were a 6.5, I'd suggest temporarily raising the fuel viscosity by using motor oil in a 10% mix to help determine whether the problem is due to a worn fuel injection system. Can't do this with a DOC/DPF equipped 2007+ truck. But, what about B5 - B20 bio-diesel, which is approved for the LML?

Jim

[CoyleJR]

Jim has probably hit the nail on the head. My 2006 LBZ has 180k very hard towing miles on it and has never had a problem. I keep the primary fuel tank full at all times through a gravity feed from the 100 gallon aux tank. The full tank will absorb a lot of heat from the returning fuel. Additionally, I always pressure wash the fuel cooler when I wash the truck.
So far so good.
John

[Kennedy]

After numerous calls with same issue over the years I FINALLY came across a loyal (new) customer who not only believed me, but patronized his source of free Tech advice. We sent him 8 fresh Bosch injectors and problem solved. Had the old ones tested and just as I have been saying al along, they were shot. Backflow rates were 2x stock on 5 of the 8 and 1.5x stock on the remaining 3. Problem was solved with fresh injectors.

[More Power]

After numerous calls with same issue over the years I FINALLY came across a loyal (new) customer who not only believed me, but patronized his source of free Tech advice. We sent him 8 fresh Bosch injectors and problem solved. Had the old ones tested and just as I have been saying al along, they were shot. Backflow rates were 2x stock on 5 of the 8 and 1.5x stock on the remaining 3. Problem was solved with fresh injectors.

Worn injectors are certainly a possibility. No question there. There is a specific fuel return flow test that the dealership could perform, but they could not duplicate the hot-hot conditions under which the codes set.

What would injector retailers and installers do if new injectors didn't help? This problem could also be due to the CP pump/FPR.

What if... cooler fuel allowed the engine to remain code free?

[Kennedy]

Maybe we could get Mark Rinker to do a water mist injection on his fuel cooler and see if that helps.

[Mark Rinker]

Interesting timing on this last comment...85F day in Kentucky I75 mountains today and reset the code too many times. Filled the tank and expected it to slow down, but it remained pretty consistant.

Was thinking about a cheap experiment with doubling the fuel cooler size. Misting would also be interesting.

Coyles experience with additional filtration and high fuel capacity sure sounds encouraging, especially if the towing is heavy, hot, and uphill. Maybe he'll chime in to tell us more about what is typical loads and such are...max loads/max hills?

[Mark Rinker]

After numerous calls with same issue over the years I FINALLY came across a loyal (new) customer who not only believed me, but patronized his source of free Tech advice. We sent him 8 fresh Bosch injectors and problem solved. Had the old ones tested and just as I have been saying al along, they were shot. Backflow rates were 2x stock on 5 of the 8 and 1.5x stock on the remaining 3. Problem was solved with fresh injectors.

Tell ya what John, until my sprays won't spray anymore I am pushing the button

How much for a custom tune that eliminates the P0087 altogether? Seems to me that its a 'bug' in the ECM, not a hard part problem, although I am sure you are right that fresh sprays would correct it - for another 125K miles or so...

[Mark Rinker]

My hypothesis is that a larger fuel cooler, and/or fuel cooler misting would reduce the number of occurances, to the extent that it could keep fuel temps at or below 160F as observed earlier in this thread. I don't think it would eliminate the codes being set, for how I thrash these trucks in the late summer running mountains and tall/wide boats.

Clearly its a symptom of high gallon injectors - miles has nothing to do with it, its the # gallons of fuel through them that wears them out.

My 2006 and now my 2009, doing exactly the same work with exactly the. same trailer with exactly the same driver and exactly the same loads started to fail at EXACTLY THE SAME MILEAGE.

Suprised? Nope.

I am on a mission to program around this, and keep treating fuel and running rail cleaner to see how long I can keep the injector tips happy. Then I'll probably take the 5K and trade on a 2011. But thats just me, and this is a business truck, which is sort of like a carpenters hammer. They wear out, I get a new one.

Ever wonder why JK hasn't rolled up his sleeves in the last few YEARS we've known about this, and delivered a clean solution to the programming problem GM created?

Hmmmm....

[Kennedy]

Tell ya what John, until my sprays won't spray anymore I am pushing the button

How much for a custom tune that eliminates the P0087 altogether? Seems to me that its a 'bug' in the ECM, not a hard part problem, although I am sure you are right that fresh sprays would correct it - for another 125K miles or so...

It's not that easy. In fact I am not sure that it could be done entirely. The issue is available tables may not list everything. Fresh injectors, filtration, lift pump, and additive would be interesting.

My hypothesis is that a larger fuel cooler, and/or fuel cooler misting would reduce the number of occurances, to the extent that it could keep fuel temps at or below 160F as observed earlier in this thread. I don't think it would eliminate the codes being set, for how I thrash these trucks in the late summer running mountains and tall/wide boats.

Clearly its a symptom of high gallon injectors - miles has nothing to do with it, its the # gallons of fuel through them that wears them out.

My 2006 and now my 2009, doing exactly the same work with exactly the. same trailer with exactly the same driver and exactly the same loads started to fail at EXACTLY THE SAME MILEAGE.

Suprised? Nope.

I am on a mission to program around this, and keep treating fuel and running rail cleaner to see how long I can keep the injector tips happy. Then I'll probably take the 5K and trade on a 2011. But thats just me, and this is a business truck, which is sort of like a carpenters hammer. They wear out, I get a new one.

Ever wonder why JK hasn't rolled up his sleeves in the last few YEARS we've known about this, and delivered a clean solution to the programming problem GM created?

Hmmmm....

The LBZ would have been easier. Again I get the calls, tell them what I have observed and never hear back. I have not had opportunity to even ride in one that has had this issue. The LBZ I think could be fixed more easily, but when I did try a mail order deal the guy said that what I did made it worse...

[More Power]

Maybe we could get Mark Rinker to do a water mist injection on his fuel cooler and see if that helps.

I don't think everyone gets the reference.... I think I still have the spray bottles I used in a TIC story a few years ago...

On a more serious note, we all know that the 6.5 community has suffered for a long-long time by dealer diagnoses that pronounced the DS4 electronic fuel injection pump as needing to be replaced for just about any sort of engine running problem. In some of those cases, it was the pump, and in many others it wasn't. Good troubleshooting eliminates the other possibilities before jumping to the most expensive solution - like changing head gaskets instead of looking for a spun impeller on a water pump.

On the other hand, if a prognosticator is so absolutely positively convinced of his diagnosis, it should come with a money back guarantee. That would be a big convincing selling point...

On another note, I saw your pic & stuff in Diesel Power mag. Good job!

Jim

[Mark Rinker]

Interesting observation from yesterday...

Loading a large boat in sweltering temps yesterday near Ackworth, GA. So hot that I left the truck running with AC on so I could take few breaks to avoid heat overload...

After I left the marina, loaded and hit I-75, immediately started getting the P00087 codes. Reset 3-4 times in the first 15 minutes and then it started slowing down in frequency...

So, under only AC accessory load idling either the high return rates heated up 3/4 of a tank of fuel (doubtful) - or high underhood temps alone are enough to cause the low fuel rail pressure code. THIS IS A VERY TELLING OBSERVATION OF THE PROBLEM, IMO.


Also it appears that the problem has not come up on LML trucks - so possibly GM changed their programming?

[Mark Rinker]

Maybe we could get Mark Rinker to do a water mist injection on his fuel cooler and see if that helps.

No, I didn't get it - but should have considering the source.

>>> After numerous calls with same issue over the years I FINALLY came across a loyal (new) customer who not only believed me, but patronized his source of free Tech advice. >>>

JK - I am not going to buy new injectors. I am not going to buy your Mega filter. I am not going to buy your vaccuum gauges, either. No cases of FPPF. It has nothing to do with believing you. Its also not because I am simple, or stubborn. It is a simple cost/benefit decision based on how I use and freqently trade my power units for my business. Period.

Over the years, I've run your LB7 and LBZ tunes with great results. I've purchased 6.5 and Duramax lift pumps, two sets of boost/EGT gauges, two sets of shocks, an EGR block-off plate, a case of FPPF and an hour of dyno tuning. This is what I can think of, off the top of my head. Q: Who is the loyal customer?



“You can make more friends in two months by becoming interested in other people than you can in two years by trying to get other people interested in you.” ― Dale Carnegie, How to Win Friends & Influence People





The same applies to sales, JK. Get interested in the P00087 limp problem programmatically and I'll be your customer...again. I have tons of real world experience that can be tapped into, if you stop selling, and start listening.