Another P0148 issue...seeking advice

[inksmith]

So, posing a question to all 5.9 owners about the ever mysterious "P0148, Fuel Delivery Error" DTC. I upgraded the transmission over 2 years ago to take an aggressive tune, installed CL on my Bully Dog back in Sept '13 and got the code the first time in Oct '13. A few more came that Nov, but I never noticed any power problems till that Dec when it lost all power with wisps of white smoke going uphill. I replaced the filters and FCA as directed but that didn't get rid of the problem. I continued getting the code until I finally took the truck down to stock completely and replaced the FCA a second time this past June. I hadn't heard a peep from the truck until Nov when it threw the code three times in as many days, the third time losing power on a flat interstate in VA BCH. We assumed the BD lift pump had gone bad and sent it in for warranty, but a week after driving it the code came back with the same power loss going up a bridge.

I've put four FCA's on this rig, replaced filters, installed a new BD lift pump and I'm still having issues. My Cummins guy and I are going to delete the factory filter and torque the tubes this week, and plan on removing the BD pump for a FASS system eventually. But something in my gut is telling me the CP3 is worn out from CL's high pressure demands, and a failed BD pump. Just want to get a feel for what everyone else may think. Thanks in advance!

 

[AllianceDiesel]

You need to monitor demand rail pressure and actual rail pressure to see what is truely going on. I just got my butt kicked on a 04. Pulled it into the garage for hard starts, did an injector return test. Was slightly higher than spec but I have seen worse. Did a lift pump flow test, again not the greatest but not the worst. Did a cp3 output test and it was like 5 times the output. Put everything back together and it will not fire. Finally got a scan tool to read pressure and only had 80psi at the rail. For some reason, once I opened the cp3 to fuel rail line the injection pump just up and quit. Installed new cp3 and she started right up. So moral of the story and for future reference, you need to be able to see actual and demand rail pressure to diagnose your problem and hard/no starts

 

[inksmith]

Hmmm, demand vs. actual, this is new. We have the scan tool and are looking at 2100psi before cranking, and 6600-7200psi at idle (which a year ago was around 8400psi). I believe that is the actual you speak of, but how do we look at demand? My money is on a worn out CP3, nothing really points to the injectors they run fine during tests. We'll find the problem eventually. Thanks for the input, how's your MegaCab running? I need to put down a signature, after 5+ years, but this trouble is with my 06 MegaCab at 124K miles.

 

[AllianceDiesel]

Its either called demand or command. Cant remember right now. Its pretty much what the ecm is telling the fca to set rail pressure to.

My mega is doing good. Has a slight miss at idle that only i can hear and it drives me nuts. So with 224,000 miles on the injectors, i got a new set sitting in the garage as well as a new fca. Now im wondering what cp3 is gonna do. But I can monitor that with efi live and my insight cts

 

[inksmith]

Well, I know I can make it to 200K, just going to take some work. I was just telling the wife I should've bought a set of injectors for a rainy day back when it was just a drop in the bucket, but that's hindsight at this point. I hear you with the small "ticks" our rigs have, mine just seems to have a shake that only I can feel! But it's in great shape, and has a lot of life left in it.

My tech and I are just baffled by this code, it seems to bother him more than me which I find hilarious. "It doesn't say what's wrong with it, you literally have a list of possible problems, most of the parts are expensive, and I don't want to play a crapshoot with your finances!" He read somewhere that a guy replaced almost his entire fuel system, lift pump to injectors save a sensor or two there, and it turned out to be the MAP sensor!

 

[cerberusiam]

P0148 High Pressure Common Rail (HPCR) Fueling Error Checksum

This is not a mechanical issue, this is an electrical issue and that opens the door wide for problems. A checksum error means the RP sensor either threw some weird numbers back to the ECU thta were unexpected or there is dead spot\spike in the reading range.

This could be a bad RP sensor, a failed PRV that is opening and not seating, it could be a bad battery connection, or even a bad FCM\TIPM throwing garbage into the system. It could also be a CP-3 mechanical failure at a certain point in the pressure range.

Could be a fan clutch going bad, could a harness rubbed threw somewhere that is partially grounding. You run the basic tests on injectors, CP-3, PRV, start cleaning up electrical connections, then replace the sensors and try again if you don't find something obvious.

 

[TRAMPLINEMAN]

Was the BD pump the Flow Max pump?

 

[inksmith]

We just got it in the bay yesterday and decided to move forward with the FASS system along with the filter delete, so next week will be able to put it on a bridge and test again. YES though, electrical makes sense, but only to a point. She runs fine, throws a code, and had been just that...a simple code that I could drive on and clear. Now when we start talking about steep inclines and her falling on her face is where I'm thinking the CP3 is going out. But, almost forgot, since we decided to add the FASS, my mechanic decided to remove connectors, cleaned, and reinstall with dielectric grease. I have read about the fan clutch going bad and throwing odd codes, and from time to time, I do get "Fan Intermittent" code. Thanks for adding to the discussion.

I can't be certain without looking, but I wanna say YES to the Flow Max as well. Whatever it was, it went bad, BD replaced, and that didn't help. But since it's gone bad and has a history of doing so, we're not taking any chances, replacing with FASS next week.

 

[cerberusiam]

Now when we start talking about steep inclines and her falling on her face is where I'm thinking the CP3 is going out.

Maybe, just as likely not. That is going to be dependent on several, chiefly engine load. Fuel level and ability to pull the fuel will also cause a lot of the same symptoms. Not sure what year your truck is but it is not unheard of a hole in the draw straw will cause some strange reactions.

As a rule, if you have issues with the CP-3 it is going to be under high rpm high load high demand conditions. If it is bad enough to effect low rpm operation almost always you end with idle quality issues or starting problems. A RP gauge is going to tell you what is happening to a degree but not neccessarily the soure. Nose diving rail pressur emay not always be a flow condition or a mechanical problem, it just as well be an elecricla issue causing it.

These systems are not the same as we are used to dealing with whne there is a jerk pump invloved. The ECU has the abiltiy to adjust duration to compensate for low pressure, to a degree. Usually when it hits the end of what can be done you get a ig jerk in the engine then it recovers. That is going to happen every time under the same conditions. An intermittent code accompanied by a power loss and white smoke could be flow tailing off or an electrical glitch in the ECU, sometimes it is hard to tell which is the most obvious.

If you CP-3 is actually weak you should be able to replicate the systems on flat ground and high load conditions. If this is happening on steep grades you have to think about the consistency it happens in relation to the load. There are a lot of things that have to work right and sometimes little things will happen that don't always have a clear source.

 

[inksmith]

I do need to put up a signature, haven't figured this site out yet. The truck is a 2006 MegaCab 4WD, BD transmission, Turbo back exhaust, AFE intake and intake horn.

You kinda summed up my thought trail for the last 14 months. A year ago, when I first had the power loss symptoms on the hills of Route 29 in Charlottesville, I had trouble keeping the code clear. It came back twice at idle. This past November is when it started losing power on flat terrain, but not consistently. And the last time I drove it, Wednesday was the first time it died after starting.

So, as stated we've cleaned connections, have removed the filtration and lift pump, and waiting on the FASS system to install. I don't think this will completely fix the issue, it will streamline things definitely. If it does fix it, problem solved, if not its at least narrowing things down a little bit.

 

[cerberusiam]

It is an 06 so thta raises the chances of electrical problems a bit more. These intermittent issues are the worst to track down,no clear indicator what is really going on. If you can't replicate the problem on demand it is tough to log data or even look at all the gauges when it happens.

An ECU or CP-3 are close in price and could both be the source of the issues.

 

[inksmith]

We isolated it down to the fuel rail. Placed a BD plug in place of the check valve, took it up some steep inclines, and no codes! This is running parallel to a separate thread with the same year vehicle, running the same program, with the same DTC problem...replacing the check valve worked on said thread, and seems as if a worn check valve was the cause of mine as well.