LBZ: low rail pressure

[LBZ]

Weak fuel rail saftey valve just a suggestion to do a bottle test

http://www.duramaxdiesels.com/forum/showthread.php?t=1995&highlight=bottle+test

Hope this helps.
FWIW the only low rail issues I have had was due to the FPRV. If at first it doesn't leak then drive around a bit and try to make it pop.

Brandonkinney have you checked your engine oil to make sure there isn't an excess of fuel in it-from a hung injector or something? Also see if you can get someone with a Tech II or EFI Live to check your balance rates if you don't have it yourself. This might help eliminate injectors as being the issue.

 

[brandonkinney]

im located in west memphis arkansas, and see the way this guy was talking i really figured he knew what he was talking about. if it was a dertroit or cummins i could have already fixed the problem. the dmax i have ever worked on. so im still kinda a green horne on it. and i have checked my oil to make sure it didnt fuel or coolant in there and its still just black oil its not runny which would indicate fuel nor is it milky to show signs of coolant in the oil. so im racking my brain. so what i need to do is see if i can track someone down with a techII or efi live. anybody have one that lives around crittenden county arkansas. like i said earlier other than dealer. i really dont know anybody else. and i dont want to get raked over the coals. because i am a mechanic my self. but this one is throwing curve balls at me. and i learned a long time ago. if your not for sure ask for help.

 

[JoshH]

When you primed the fuel filter with the pump on the filter housing did you open the bleed screw on top of the filter housing until good clean fuel was coming out (no bubbles) then close the bleeder and pump some more until it got firm?

 

[brandonkinney]

no i didnt do that. maybe i should try that to see if there is any air in the system. thats a great idea. like i said eariler when it happened to me again i was about 10 degrees past p**sed off. but im fixing to start working on it again since i got that da** air cast off my foot. those things just truely suck lol. ill try that and if that dont work if i can get it started and stay running i also plan on doing a bottle test and see what happens.

 

[dbwear2000]

I also have a 2006 and have been getting the P0087 code a lot. At first I thought it was the filter, but after changing it the code would come back about 2000 miles later. I must have gone through $300 worth of filters needlessly. This is a problem many owners have...Chevy and Ford, don't know about Dodge. My mechanic noticed right away that my fuel cooler was extremely dirty so the fuel was hot getting to the engine and possibly causes some rubber lines to collapse on itself restricting fuel flow. He cleaned my cooler and the code is still thrown but much less frequently. Mine seems to happen when pulling a load up hill in hot weather when my engine is running slightly above normal. In my case, I have a code reader to clear the code when it happens and then it seems to run fine. Once I stop and let the engine cool a bit, everything is back to normal. Also there are fixes from PPE...here are the links: http://www.pacificp.com/store/index.php?main_page=product_info&cPath=2_7&products_id=114 and http://www.pacificp.com/store/index.php?main_page=product_info&cPath=2_7&products_id=53. I haven't gotten them yet, but am seriously thinking about it. Hope this helps...sorry its so long.

 

[JoshH]

I also have a 2006 and have been getting the P0087 code a lot. At first I thought it was the filter, but after changing it the code would come back about 2000 miles later. I must have gone through $300 worth of filters needlessly. This is a problem many owners have...Chevy and Ford, don't know about Dodge. My mechanic noticed right away that my fuel cooler was extremely dirty so the fuel was hot getting to the engine and possibly causes some rubber lines to collapse on itself restricting fuel flow. He cleaned my cooler and the code is still thrown but much less frequently. Mine seems to happen when pulling a load up hill in hot weather when my engine is running slightly above normal. In my case, I have a code reader to clear the code when it happens and then it seems to run fine. Once I stop and let the engine cool a bit, everything is back to normal. Also there are fixes from PPE...here are the links: http://www.pacificp.com/store/index.php?main_page=product_info&cPath=2_7&products_id=114 and http://www.pacificp.com/store/index.php?main_page=product_info&cPath=2_7&products_id=53. I haven't gotten them yet, but am seriously thinking about it. Hope this helps...sorry its so long.

How many miles are on your truck, and what mods do you have? I seriously doubt those products from PPE will fix your problem.

 

[brandonkinney]

o.k. guys i found that the bleeder screw was loose and i think that was causing it to suck air. so i bled it till nothing but fuel come out (no bubbles). tried to start it and it didnt start. so i primed the filter a little more. and she finally hit. and it seems to be running fine. drove it around town and dogged it when i could do to the cops running around.lol. but when i hammered down on it. a nice size puff of dark black smoke would come out the tail pipe and that has never happen before. normal driving it wouldnt do it. only when i hammered down on it. now i know with 18 wheelers. when it puffs black smoke it is usually a injector problem would this be the same case with the dmax's. and if so r they like the injectors for big trucks and r rebuildable.

 

[jevanb]

when my injector stuck it blew so much white smoke I could not see traffic behind me, also the truck would not run because no rail pressure (all pressure going out the stuck one) if your glow plug lit and you hit the engine with starting fluid you would have more problems then you have now (they do not like to run backwards). normal for a puff of smoke on a factory tune wait till you put in a aftermarket tune, the injectors are rebuildable but not buy you.

 

[Philtopgun]

have a friend that just bought a LBZ with 60k miles. He did ppe trans, AD165, idaho dsp5 tune, and 3 fuel washers... he did this all within the week. After placing the idaho tune and ppe trans, he started with the same low fuel pressure code. He then added the AD165 and 3 washers... He only logging 15k on fuel pressure and still throwing the low fuel pressure code. He trucks seems a lot faster off the start than mine and will black smoke all the way to 90 then throw the code... you can command 160, but will only do about 15k.... cant find fuel leak...

 

[jevanb]

when it puffs black smoke it is usually a injector problem .

no, it is normal even for big rigs it is lack of air and too much fuel, if it is a injector sticking open it will smoke white

 

[ikeG]

If it was a bad bleeder screw, the rail press would be erratic i think. Would run fine then shut down unexpectantly some times. Would crank a lot before firing too. Just fixed a LLY that would shut off then run fine sometimes. If you watched rail press while cranking it would have nothing and then all of sudden come up and start.