PDA

View Full Version : Question for diesel truck owners specifically GMC?


jkski
09-17-2011, 07:57 AM
I have an 06 GMC D-max that threw a code yesterday, P0088, which is the code for Fuel Rail/System Pressure Too High and it causes the truck to greatly reduce power and it sounds more like a Cummins. So, I changed the fuel filter hoping that might resolve the issue but it has not and from looking on dieselplace.com it seems as though the Fuel Pressure Regulator is my likely problem.

So, my question is, will I hurt the truck by driving it until I can get it to my mechanic on Monday? Other than the power loss and the increased diesel engine cackle, everything seems fine.
I've posted this same question on dieselplace.com but thought someone on here might know as well.

tommcat
09-17-2011, 09:22 AM
I wouldnt drive it too far unless absolutely necessary. while i dont know that engine specifically i know that with fords, engine damage can and does sometimes happen from fuel system issues and the gm system isnt too much different.

Thrall
09-18-2011, 11:46 AM
Ask on dieselplace. Lot's of helpful DMax gearheads on there, just like MC guys here.
Have you tried clearing the code and see if it runs better? Can use code readers at Autozone, etc for free.

Cloaked
09-18-2011, 12:51 PM
I have an 06 GMC D-max that threw a code yesterday, P0088, which is the code for Fuel Rail/System Pressure Too High and it causes the truck to greatly reduce power and it sounds more like a Cummins. So, I changed the fuel filter hoping that might resolve the issue but it has not and from looking on dieselplace.com it seems as though the Fuel Pressure Regulator is my likely problem.

So, my question is, will I hurt the truck by driving it until I can get it to my mechanic on Monday? Other than the power loss and the increased diesel engine cackle, everything seems fine.
I've posted this same question on dieselplace.com but thought someone on here might know as well.Here's a place to start.... Good site, knowledgeable people....

http://www.thedieselpageforums.com/tdpforum/showthread.php?t=35576&highlight=P0088

Let it sit until Monday...

.

.

jkski
09-19-2011, 07:57 AM
Ask on dieselplace. Lot's of helpful DMax gearheads on there, just like MC guys here.
Have you tried clearing the code and see if it runs better? Can use code readers at Autozone, etc for free.

I have a nice Mac Tools code reader that comes in very handy for things like this and unfortunately, even with clearing the code the problem still persists. So, the truck is now sitting with the mechanic hoping that it is only the Fuel Pressure Regulator as was suggested by some of the threads on the various diesel forums.
Thanks for the advice.

Thrall
09-19-2011, 06:47 PM
I think the fpr is kind of a common failure. Never had ANY problems with my 02 LB7, so cannot comment. Not a large repair either.

tplane2
09-19-2011, 09:27 PM
Don't drive it too far, could cause damage to the injection pump. Usually damage is caused by low rail pressure, but too much pressure could also damage it.
The fpr could be faulty, or also the fuel rail valve could be stuck/bad. Could be a number of things, get a good scanner to go more in depth.
Just my .02 from a fellow LBZ owner...

91ps190
09-24-2011, 07:22 PM
It sounded like a cummins - so you gained power???????????????:D

chawk610
09-26-2011, 07:27 AM
We have a fleet of 2500HD's at work... wondering if you had an injector or two go out on you????

jkski
09-26-2011, 07:41 AM
No update yet, the jury is still out as my mechanic is taking his sweet time....time to find a new mechanic I maybe!
From all of the posts I have read on other forums regarding this code, the FPR seems to be the common culprit follwed by possible injector issues and or lift pump.....my luck it will be all 3!

I'll let you know what the final solution is if I ever find out.
Thanks again for the input, it is appreciated.

Thrall
09-26-2011, 07:57 PM
No lift pump on a DMax unless it's aftermarket.
You probably mean the injection pump (Bosch CP3) which is not cheap. Get a 2nd opinion of they tell you it's the inj pump as the FPR is in line after the pump and typically the only problem with the pump is not enough pressure. Same with injectors. If they tell you it's a bad injector as for a balance rate test on your injectors if they haven't done that then they can't tell if the injectors are bad.

Cloaked
09-26-2011, 09:12 PM
No lift pump on a DMax unless it's aftermarket.
You probably mean the injection pump (Bosch CP3) which is not cheap. Get a 2nd opinion of they tell you it's the inj pump as the FPR is in line after the pump and typically the only problem with the pump is not enough pressure. Same with injectors. If they tell you it's a bad injector as for a balance rate test on your injectors if they haven't done that then they can't tell if the injectors are bad.Kennedy Diesel for a nice lift pump setup. They are worth the investment.

Thrall
09-27-2011, 01:50 AM
Kennedy Diesel for a nice lift pump setup. They are worth the investment.

I get it for high power applications, but my LB7 never ran out of fuel even on the Edge Juice level 6 (150hp or something).
What I don't understand is why Cummins motors with essentailly the same CP3 feeding similar injectors need a lift pump even in stock configuration and DMaxes don't.:confused:

timvan
09-27-2011, 07:17 AM
I get it for high power applications, but my LB7 never ran out of fuel even on the Edge Juice level 6 (150hp or something).
What I don't understand is why Cummins motors with essentailly the same CP3 feeding similar injectors need a lift pump even in stock configuration and DMaxes don't.:confused:

The cummings would run without a lift pump as well. You can add a lift pump to your dmax, I put a tts unit in mine and its a major difference. It will also prevent premature cp3 failure as the fuel is always under pressure waiting..

tplane2
09-27-2011, 07:41 AM
I get it for high power applications, but my LB7 never ran out of fuel even on the Edge Juice level 6 (150hp or something).
What I don't understand is why Cummins motors with essentailly the same CP3 feeding similar injectors need a lift pump even in stock configuration and DMaxes don't.:confused:

The Cummins lift pump is inline from the tank to the CP3, just as if you put an aftermarket on a Duramax. But if the Cummins fails, the way the pump is designed causes to much restriction for fuel to flow under throttle, unlike the aftermarket pumps for GMs. So if the pump was completely removed, it would/could run better than if was pump was still inline and bad.
Dodge put it on there for the same reasons we put aftermarkets on ours (cp3 life and performance). Just at a lower gallons per hour rate, less flow.

The cummings would run without a lift pump as well. You can add a lift pump to your dmax, I put a tts unit in mine and its a major difference. It will also prevent premature cp3 failure as the fuel is always under pressure waiting..

It would run, but as soon as you put throttle in, it would fall on its face.

jkski
09-27-2011, 07:55 AM
Everything on the truck is stock so as you stated, no lift pump....I am learning!
The truck went to the dealership yesterday for a second opinion, so we will see what the verdict turns out to be.
I appreciate the advice and will be sure to ask the questions suggested if need be.

Thrall
09-27-2011, 05:10 PM
Hope you get it sorted out quickly now. I'm not as patient as you and would have someone's @ss by now if my truck sat for a week and the mech didn't know what was wrong with it!

tplane, so you're saying if you eliminated the lift pump completely on a Dodge it would or wouldn't run well?
Not discounting what anyone is saying and I know lots of poeple put lift pumps on DMaxes and lots go to aftermarket LP's on Cummins', but if there's a million Dmaxes running around with the same inj pump pushing the same Bosch CR injectors (2 more in fact not that it really matters), at the same rail pressures and they run fine for lots of miles, then why would Dodge put a LP behind their CP3 on the Cummins? Seems counter intuititve.

I had a Dmax, got rid of it when it was still a baby at 100k mi, but ahve seen ALOT of them running around with 200-250k mi on the orig CP3.
Now got a Dodge 5.9 CRD with a LP. Is it really going to make the CP3 last longer? Even if the LP doesn't take a crap and starve the CP3, killing it?

jkski
10-06-2011, 09:05 AM
OK guys, here is a new one for you. I finally got the FPR replaced (by the dealer) and picked the truck up yesterday. As soon as I started it, I knew it was not right as I could still hear some of cackling noise although the fuel pressure, temp and oil pressure were all good. Talked to the tech before I even drove it away and he said to drive it and see.....never a good sign I know.
So, I proceeded to drive it 20 minutes to pick-up my boat and by the time I got there, the cackling had increased and the truck was idiling very rough, but the power was good as it was before I ever had the issue. So, I hooked onto the boat and drove about 2 minutes down the road and the truck fell flat on it's face, acting just like it did prior to the FPR being replaced. The cackling was back in full force and there was very limited power....barely pulled the 197 back to the garage.
So, it's back at the shop but does anyone have any thoughts? I have already posted this on the duramax site and dieselplace but truthfully you guys are better at responding.
The most troubling part about this is that when I picked it up, other than the reduced cackling noise (which a Duramax does not normally have), the truck ran fine, so it leaves me to wonder if there isn't something damaged internally? Could it be something as simple as an injector gone bad or maybe the transfer pump?
Thanks in advance.

jkski
10-06-2011, 11:54 AM
New update on the saga:
Mechanic/Tech just called and said that injector #5 is bad and staying open, so the good news is that this would explain why is was running badly even after having replaced the FPR, the bad news is that he stated that if 1 injector goes bad then others generally follow suit. So, my questions now are:
1) Could a bad injector cause the knocking/cackling noise I was hearing?
2) How likely is it that other injectors will soon follow in failure?

Thanks in advance.

tplane2
10-06-2011, 05:27 PM
Hope you get it sorted out quickly now. I'm not as patient as you and would have someone's @ss by now if my truck sat for a week and the mech didn't know what was wrong with it!

tplane, so you're saying if you eliminated the lift pump completely on a Dodge it would or wouldn't run well?
Not discounting what anyone is saying and I know lots of poeple put lift pumps on DMaxes and lots go to aftermarket LP's on Cummins', but if there's a million Dmaxes running around with the same inj pump pushing the same Bosch CR injectors (2 more in fact not that it really matters), at the same rail pressures and they run fine for lots of miles, then why would Dodge put a LP behind their CP3 on the Cummins? Seems counter intuititve.

I had a Dmax, got rid of it when it was still a baby at 100k mi, but ahve seen ALOT of them running around with 200-250k mi on the orig CP3.
Now got a Dodge 5.9 CRD with a LP. Is it really going to make the CP3 last longer? Even if the LP doesn't take a crap and starve the CP3, killing it?

From what I've been told: Yes, it would run the same as a Duramax. IIRC Dodge put them on the for longevity and ease of prime.
You are correct there are tons of Dodges with lots of miles, but how old are they really compared to Duramaxes. Are you thinking P-Pumps or the VP44 (?) from the CRD 03-07. The stock cp3 on a duramax lasts about 200-250k. Thats without any fuel demanding performance upgrade added. IMO thats not very long.

New update on the saga:
Mechanic/Tech just called and said that injector #5 is bad and staying open, so the good news is that this would explain why is was running badly even after having replaced the FPR, the bad news is that he stated that if 1 injector goes bad then others generally follow suit. So, my questions now are:
1) Could a bad injector cause the knocking/cackling noise I was hearing?
2) How likely is it that other injectors will soon follow in failure?

Thanks in advance.

1) Possibly
2) Probably sooner than later. The fuel systems on diesels are pretty delicate as far as malfunction due to contamination. Usually if one injector has prematurely failed it was due to fuel. Thats why most people replace all injectors if one goes down. If you keep clean/waterfree fuel you can run a while on the stock fuel system. But like Thrall said, it all depends on the balance rates of the injectors. So go check and make sure they are +/- 4 at park, and +/- 6 in drive at idle, motor warmed up.
Also...It sounds like the technician who is working on your truck doesn't know what he is doing.

Cloaked
10-06-2011, 07:51 PM
New update on the saga:
Mechanic/Tech just called and said that injector #5 is bad and staying open, so the good news is that this would explain why is was running badly even after having replaced the FPR, the bad news is that he stated that if 1 injector goes bad then others generally follow suit. So, my questions now are:
1) Could a bad injector cause the knocking/cackling noise I was hearing?
2) How likely is it that other injectors will soon follow in failure?

Thanks in advance.Look, here's the bottom line ....believe it or not. I have been through this with 4 sets of injectors with the Duramax. You have a failure of the fuel rail, pump, and injectors. It is a commonly known and inherent problem that many have experienced. Go to any GM diesel forum and read about this issue multiple times.

Costs anywhere from $4,500 - $6,500 to have this isssue resolved and depending on the replacement parts, you may encounter it again sooner than later.

Pay up or get rid of it. Simple as that unless your GM people < spit > are willing to convince the warranty idols to pay for it. From my experience and opinion, the Duramax is crap. Always has been and always will be. I started with the LB7 (two of them - 2001 and 2002 models) and I am on my last Duramax in the LBZ engine (2007 classic body). As soon as I find a convenient time to swap, I'm going back to a gasser. Diesels this day and age in light trucks are nothing but a hobby. They do no real work with life-expectancy, trouble-free expectations.

Best of luck.

.

Thrall
10-17-2011, 05:49 PM
[QUOTE=tplane2;794207]From what I've been told: Yes, it would run the same as a Duramax. IIRC Dodge put them on the for longevity and ease of prime.
You are correct there are tons of Dodges with lots of miles, but how old are they really compared to Duramaxes. Are you thinking P-Pumps or the VP44 (?) from the CRD 03-07. The stock cp3 on a duramax lasts about 200-250k. Thats without any fuel demanding performance upgrade added. IMO thats not very long.



I was speaking of the CR Cummins. So do the Cummins CP3's really last that much longer with a lift pump? (Just asking, I don't have any high mileage experience with either although I own/owned both.)
Ease of priming is nice too, never have to prime after a filter change with the Dodge.

Thrall
10-17-2011, 05:54 PM
New update on the saga:
Mechanic/Tech just called and said that injector #5 is bad and staying open, so the good news is that this would explain why is was running badly even after having replaced the FPR, the bad news is that he stated that if 1 injector goes bad then others generally follow suit. So, my questions now are:
1) Could a bad injector cause the knocking/cackling noise I was hearing?
2) How likely is it that other injectors will soon follow in failure?

Thanks in advance.

How many miles n the truck? Less than 100k I presume since yuo have it at the stealer.
All the other injectors don't necessarily follow. Besides the LLY on up engiens are easier to change injectors, I wouldn't do all 8 jsut because.
Did they check the balance rates like I suggested? That will tell you if any others are on the edge or not. Also if #5 was staying open, how much fuel did you push into the crank case? Was the oil level overfull?
I saw you other thread about the backorder.
Best suggestion I got is to get over on diesel place and let those guys steer you in the right direction.