Dmax limp mode, fuel rail pressure too low - Anyone else?

A few weeks back I went on a working trip that involved one of our major mountain passes.

It was hot out, I'm towing my 27' TT with my D/A dually and I no sooner hit the beginning of the Coquihalla Highway, a very steep mountain pass, and my truck suddenly lost power, check engine light came on and it went into limp mode. Argh! Won't rev over 2000 RPM. I limped it all the way to Kamloops, some hundred miles away. I stopped for fuel, then carried on. I stopped at a store for some supplies and when I came out and started it up, check engine light was out and the truck ran normal again.

I went another hundred miles or so, did my work and headed home, everything ok. As soon as I got back to Kamloops and hit the big hill again, same thing happened. I got part way up a long hill in limp mode, turned around, found a dealer and had them read the code.

P0087 - Fuel rail - pressure too low. They reset it and I went on my way home but the light came back on right away.

I limped all the way home and when I got out of the mountains and on the flats at the coast again, problem went away. Dropped the TT at storage and the issue never came back again.

Took truck in for service, oil change and had them put a fuel filter on it. Hopefully this makes a difference. Old one had a lot of miles on it.

Fast forward to last weekend - grabbed the TT and headed to BC's Okanogan Valley to take a couple of my grandsons camping. Shortly into the mountains on Hwy 3 up a long hill, same scenario.

This time I had my code reader with me and I pulled over, hooked it up and erased the code. From there on I made sure I used manual mode, kept the revs up and didn't labor the engine too much. It happened one more time before I reached Penticton, our destination.

Had a great weekend with the grandsons and headed home, driving cautiously. No problems on the way home, even up a long major grade out of Princeton on Hwy 3.

This Friday I am heading up to BC's Cariboo region for the Labor Day long weekend. I am concerned about this issue. I don't have time to take it to the dealership for their expensive "throw all new parts at it" attitude.

Anyone else have this problem?

Any ideas on the cause of it?

Any suggestions?

It's a real pain going up a major hill at 20MPH having all the big rigs passing me!

29 Replies

BobsYourUncle
Nomad
Sep 04, 2013
Thanks for the additional tips.
I forget the hours - guess I could run out and look, but the truck has about 132000 miles on it. I really don't want to need injectors - big ouch on the wallet.

I hadn't thought about changing the filter again. The problem lessened significantly after a new filter but it is still there, especially if I lean on it a bit on the hills, but only while towing.

I have always had the dealer change the filter. Guess I could buy the appropriate stuff and do it myself. I have just got spoiled a bit in the past number of years. I used to turn all my own wrenches. I hate the smell of diesel on my hands. Rubber gloves.....

I'll try changing it again and get a spare or two. I suppose I could have got a batch of bum fuel. I always try to buy from a high volume station, and not a little mom and pop corner store. But anyone could get a bad batch.

I might have to wait a while before I can test it out though. Don't think I will be towing in the mountains for a while.
mapguy
Explorer
Sep 04, 2013
Replace the rubber fuel line sections on the firewall and at the fuel filter housing. They collapse causing the problem. Simple cheap things first-there is a TSB on this problem. Can be worn injectors - balance rate will be an indicator. Can be a worn cp3 injection pump too. Need to investigate demanded Vs delivered rail pressures. Can be issues in the fuel regulation too.

Edit: when truck throws the code, check the fuel filter primer to see if it pumps up. If it pumps up you have a air leak or suction collapse.

Is this a high milege/hour truck?
joelabq
Explorer III
Sep 04, 2013
I bought my 2007 LBZ 35000 with the P0087 problem towing heavy. If you have around 130k+ I would bet you need a set of injectors.

I know people say LBZ don't eat injectors, but the fuel quality and lack of good filtration seem to say otherwise. I can tell you my Efi live would not hit the max command PSI on a warm truck until I replaced the injectors. All the injectors were within "spec" on the balance test.

I would also suggest doing what I did as well: Add a Kennedy Diesel lift pump and mega filter. Also, only use the GM or Racor (same thing) coalescer filter. This should keep you from burning through another set of injectors. That is unless your near buying a new truck then just forget it.

Only purchase real Bosch injectors and expect to pay $3500 to do the job yourself.
mguay
Explorer
Sep 04, 2013
It is not likely going to be injectors... that was the earlier D-Maxes! LBZ's are not plagued with that issue. Before you dig into the rubber lines...change the filter again...even twice. Every time I fuel up in NJ I go thru 3 filters before I stop getting the "fuel rail pressure too low" code and limp mode! All you need is a large strap type filter wrench and a pair of channel locks to swap the water sensor. I carry a spare behind the seat and have swapped it on the side of the road!
BobsYourUncle
Nomad
Sep 03, 2013
Ron, thanks for the link to the very useful article.

I sure hope it is not injectors. I am going to approach the simple things first.

Good article!
BobsYourUncle
Nomad
Sep 03, 2013
I just got back from a long weekend trip.

On the way up to the lake all went well, although I did use caution and dropped a gear or two up the big hills. Kept the revs up and easy on the throttle.

On the way back I made it halfway home, this time driving normally without dropping gears on the hills and it occurred once on a long hill.

I pulled over, plugged in my code reader and same code again, P0087. I reset it and drove carefully the rest of the way home without issue.

Temperature was quite warm - in the high 80's.

I am going to change out the rubber lines by the transmission and see if that helps. But I won't know until I hitch up and go up a long steep grade towing.

Best to try the cheap stuff before getting into the more costly items.

Thanks for all the help everyone.
Ron_Nielson
Explorer
Sep 01, 2013
There are lots of things that can cause your problem. Here is a link that will give you a great idea of what the problem might be ; Kennedy Diesel. And John Kennedy is one of the best in the business - he knows his stuff.

And if that isn't enough enough information, just google 'P0076' (those 0's are numeric zeroes, not alpha o's) and you will be up for a couple of days reading about the problem and possible solutions.

IF your injectors need replacement, that is likely the fix. If they're verified to be OK (not bypassing too much fuel at high temps), then the approach I wold use would be to install a lift pump with additional filtration. This supplements the existing system, makes it so that the problem is less likely to happen.
wintersun
Explorer II
Sep 01, 2013
The LBZ engine is noted for having problems with fuel rail pressure loss due to fuel supply restrictions and fuel rail pressure relief failure. It is good that it went into limp mode as the diesel fuel is in part a lubricant for the injectors and too little fuel can damage the injectors which is an expensive repair.

I would take it in limp mode to the nearest diesel shop to be checked out thoroughly. No sense risking damage to the engine and a big repair bill.
Ron_Nielson
Explorer
Sep 01, 2013
There are lots of things that can cause your problem. Here is a link that will give you a great idea of what the problem might be ; Kennedy Diesel. And John Kennedy is one of the best in the business - he knows his stuff.

And if that isn't enough enough information, just google 'P0076' (those 0's are numeric zeroes, not alpha o's) and you will be up for a couple of days reading about the problem and possible solutions.

IF your injectors need replacement, that is likely the fix. If they're verified to be OK (not bypassing too much fuel at high temps), then the approach I wold use would be to install a lift pump with additional filtration. This supplements the existing system, makes it so that the problem is less likely to happen.
TRIPLE8
Explorer
Aug 31, 2013
J-mans Dad wrote:
sounds kinda like the problem I had this summer towing over the Siskiyou grade on I-5. Every time we went above 3000 ft the CEL would come on and the truck would limp. Code reader said P0045 Turbo Vane Position control solenoid. Once we went below 3000 ft and restarted then it was fine. go figure :R
Hi, mine was like that too except for no limp mode. It kept clearing itself so I did not do anything. After about 6 months took it in and needed a new turbo. Luckily it was still under warranty.