P0087 fuel rail pressure low limp under high loads

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Originally Posted by Jeff Paxton

Just got the call from the repair shop. They said, "We did an injector balance test and the numbers are all over the place indicating you need injectors." Of course, not being a diesel tech, I can't make sense of this. All I can do is look at obvious symptoms that present when injectors are bad. I don't remember all of them at the moment, but It starts easily, idles like a purring kitten, doesn't smoke, and has power out the wazoo when not hooked up to a load. Thoughts anyone? Will this cause a starvation for fuel under load when downshifting up a hill? I am still leaning toward fuel lines as a logical reason. But when they call me with a parts quote, I want to either tell them do the fuel lines, or just tell them I'm coming to get it because I am not doing injectors regardless. The truck isn't worth that kind of expense.

Edit to add: he said "the balance rates are ranging from -.4 to 1.7 or 9 or something..." From what I am reading, anything inside of +/-4 is acceptable so...?

Just got off the phone again with the quote. $7k+ for new fuel rails and injectors. I said I am not throwing more good money after bad and I will be picking it up to limp it home. I asked specifically what the values were on the balance test... Now he said -.8 to 1.5. I didn't argue that this acceptable, what's the point? They don't want to mess with the fuel line collapse. I may pursue it a little more once I get home, with my dealership, but I will let you all know the outcome. I may just sell the whole rig and forget it.

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Yea, I believe it was Mark Rinkler from this thread that got all new injectors and it didn't help at all.

I asked this before in another post. I'm actually thinking of getting souped up fuel cooler after all the symptoms we've had. Anyone think that this sounds like a good idea to try out?

Someone on this forum that works on diesels named "DieselTech" seems to have the answer. ---> Add another fuel lift and another fuel cooler.
http://www.dmaxcentral.com/forum/showthread.php?t=5358

Anyone have thoughts/opinions on this?

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Originally Posted by Jeff Paxton

Coyle, I don't have a scanner but I think I can go easy enough to make it the 2 hours to the flats west of Omaha. We'll be leaving early in the morn, and fronts have moving through cooling things down. It doesn't take too long to clear a code manually, but it does if it is the actual "cool down" from parking that benefits it the most. I thoroughly pressure washed the fuel cooler as well. I have always gone 60 when towing the rig just for ease of handling, but I will do as Demilee and use the downhill to gain on the uphill if need be so... I think you are correct on the 87 code, have NEVER had one when it was cool/cold. And I will definitely be keeping the tank 1/2 full+. I will disconnect the fuel heater as well per DmaxMaverick's instructions. Anyway, I will let the forum know how it goes.

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Yes, we found that going 55 to 60 is best too. We were going 65 in some states. That pops the code more often. Makes sense of course. We're in CA now so can't go over 55 anyway! :) But I def have went over the speed limit here going downhill to get up hills. I figure I am more of a hazard going 30 in limp mode than going 5-10 miles over the speed limit.

Good luck Jeff!

I don't think anyone has ever posted a problem with a P0087 code on a medium duty GM truck(4500, 5500) with a D/A. Do they have something different from the standard pickup? How large is the fuel cooler on a medium duty GM truck? Are they also having trouble with the P0087 code and no one is posting it? Just some things concerning the P0087 code to think about.
John

I can't wait for the answer to that, Coyle, since that is what I'm looking at doing.
Anyway, update: We have made it to council bluffs after a later than planned start due to lack of sleep/nerves. but still got out at a decent time under cloudy skies, 78 degrees. The skies have cleared and temp has climbed to 83. I have NOT used tow/haul to avoid advancing the shift down since limp always comes at 5th to 4th. Been running in 6th mostly but did shift from 6th to 5th three times. On the second one, I did get a check engine,but no limp! It may be a different code though, I will let you all know. The coolant temp is not fluctuating as much, it did touch 215 twice.

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Originally Posted by Demilee

Yea, I believe it was Mark Rinkler from this thread that got all new injectors and it didn't help at all.

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It's my understanding that new injectors almost always solve the problem - once the other more routine possibilities have been eliminated.

Another-larger fuel cooler could work, as does an auxiliary fuel tank. In either case, it's a bandaid that might allow a set of injectors to reach design life.

I wonder if B5 or B20 bio-diesel helps or hurts in these situations because of how fuel viscosity is affected.

Jim

Well, thought we were in the good after making council bluffs/Omaha. Got a limp between Omaha and Lincoln. Just got another and we are barely out of Lincoln. After stopping to eat, came out to a pretty good wind. It's a head wind and it's killing me

Jim,
That is a very good thought about bio-diesel. I stopped using it years ago when I realized that it hurt my fuel mileage and it cost more than regular diesel. I also have an auxiliary tank that keeps my primary tank full at all times. My 190k mile, LBZ truck has never shown a P0087 code. Friday will be a test, the temperature is predicted to be 120 and I will be going east over the mountains from Phoenix Az. The total weight will be near 24k lbs and if the truck doesn't show P0087 code it never will.
John

Best of luck Coyle.

We made it. Ran 60-65 for 14 hours with about 4 for stopping to eat, fuel, and the two limps. There were no more full blown limp modes after the second west of Lincoln, until I was home climbing the last hill. Out on the flat, running 1600 rpms won't trigger it so Nebraska was great. Going into the dealership tomorrow, I'll post any news. Stressful day, I'm beat.

I just tuned a couple more locally for this issue. One has been running great since the tune. He hauls cattle (mostly calves) so he's all over the state and can be quite heavy. Only back once for CEL that was for a bad plug. The other has not been out and worked yet.

As MP suggested, the addition of a bit of Bio may help the viscosity similar to the old motor oil in fuel trick to temporarily fix DB2 hot start issues.

Lift pump, secondary filtration, and quality additive are what I prescribe for prevention.

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Originally Posted by Kennedy

Lift pump, secondary filtration, and quality additive are what I prescribe for prevention.

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Why does it appear that the LBZ/LMM are more often affected by a P0087 than the LB7/LLY?

Thanks

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Originally Posted by More Power

Why does it appear that the LBZ/LMM are more often affected by a P0087 than the LB7/LLY?

Thanks

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If I had to guess I would say that it has to do with the way that Bosch did the programming on the later models as well as possibly the direct-to injector control of the later models. Also probably emissions related.

Earlier models of course were Delphi and controlled indirectly through the FICM.

Kennedy, what about this question from Coyle? I would like to consider these on my trade if it is true.

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Originally Posted by CoyleJR

I don't think anyone has ever posted a problem with a P0087 code on a medium duty GM truck(4500, 5500) with a D/A. Do they have something different from the standard pickup? How large is the fuel cooler on a medium duty GM truck? Are they also having trouble with the P0087 code and no one is posting it? Just some things concerning the P0087 code to think about.
John

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If anything the med duty trucks are worse. The relationship between the engine and tank in both elevation and distance being greater plus the overall weight makes the pressure differential inside versus outside the lines greater to move fuel. In laymen's terms that have to suck harder to get the fuel to flow from the tank to the pump.

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Originally Posted by Demilee

Yea, I believe it was Mark Rinkler from this thread that got all new injectors and it didn't help at all.

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Hello all. For clarification, I never replaced the injectors on my 2009 K3500, the last Duramax I sold with the sale of my business. I included the Diablosport Predator LBZ/LMM handheld programmer (with code reset capability) with the truck and told the new owner all about the P00087 situation.

I had the same issues with the 2006 truck that preceded the 2009...becoming more frequent as the trucks neared 100K miles in service.



Good luck with your work-arounds.

Update: Per GM customer care request, took the diesel tech for a ride-a-long today towing the camper to try and trigger limp mode while he had his computer plugged in. Was fortunate to get it to limp twice. The temp was 88 degrees. He was frantically writing down info most of the time. So now I will wait to see what they come up with after they hash it out. Will keep you all posted.

Hopefully they modify the ECM code to widen the acceptable gap between requested and actual fuel rail pressure, in relation to fuel temperatures.

Problem solved.

Its a programming error!!!

Widening the range will likely not happen. High pressure is what gets them atomization and makes emissions. The key is to get the ECM the info it needs so it can command the pump to deliver more volume to compensate for increased return flows and maintain proper psi.

This also plays into economy and explains why many find that adding a lift pump improves response and overall fuel economy slightly. It's just easier for the ECM to maintain steady rail psi.

Going to try cleaning the fuel cooler on a 2008 here at our dealership. I think that's a great idea. We have had a lot of trucks here with that same code. Most of them just need a fuel filter, though the last one had an injection pump that came apart... That was spendy. I'll let ya'll know what we find on this one, its a 2008 with 190,000 on it. original sprays.

Also for my introduction... GM service advisor here, I am running a 2002 Chevy 2500HD 8.1/Ally... Gas guzzler but pulling machine. Thanks for the great forum

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Originally Posted by GMADVISORMT

Going to try cleaning the fuel cooler on a 2008 here at our dealership. I think that's a great idea. We have had a lot of trucks here with that same code. Most of them just need a fuel filter, though the last one had an injection pump that came apart... That was spendy. I'll let ya'll know what we find on this one, its a 2008 with 190,000 on it. original sprays.

Also for my introduction... GM service advisor here, I am running a 2002 Chevy 2500HD 8.1/Ally... Gas guzzler but pulling machine. Thanks for the great forum

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Welcome to the board! Your input is appreciated. The code P0087 is an emerging problem for the LBZ/LMM. Jim