2006 With fuel system problems,
 

Hi guys.
I've got an 06 Mega Cab with G56 and about 225,000 miles. Engine wise truck has always been 100%, except for the #5 injector line that cracked and I replaced this spring.
Lately my truck would do the deal where the wait to start light would come on while driving at highway speeds, the chime would sing 10 times and then it would usually go away. This was generally while pulling up a hill etc. Sometimes I noticed reduced power, sometimes not.
It's gotten progressively worse. I had the smarty Jr. on it set to performance so I turned it back to stock, changed the fuel filter and tested it. Truck will seemingly run fine for a few miles than it will loose power to the point the pedal feels dead before then bucking and taking off again. It will buck worse and worse and eventually stall. It will throw the P0148 code. Truck Is not making any oil. No visible fuel leaks. Lift pump can be heard running, obviously pumping Atleast to some degree as it primes and starts fine after a filter change and draining the bowl.
Any advice??

These links should give some ideas.

DTR

Back to morning brew in the afternoon . . . [coffee]

I watched the 4 videos of that series. That's a great synopsis of the Cummins fuel system.

I've got a feeling it's the FCA going bad.

Sounds like you are losing fuel pressure. Can you monitor rail pressure with your tuner? My initial feeling is after your lift pump runs for a while its heating up and losing pressure. But to diagnose it right you need to see lift pump pressure vs rail pressure. Also double check your connector tubes to make sure they are tight. Had one in the shop last year for same code and turned out to be a loose connector tube after some other shop did a head gasket.[duhhh]

Fought this code for years. Had same issues as you.- what fixed mine was bypassing the draw straw in the tank. I installed a sump- fixed my problem

I'm having an absolute nightmare trying to get the bottom screw off the FCA. The Torx head seems to be stripped, not to mention its -8F and I'm working in the driveway.

Well I finally got the stupid FCA changed. Had to take the inner fender off, and drivers front wheel, cut a slot in the screw with a dremel and turned it out with a flat screwdriver.

Test drove, same symptoms and throwing the p0148 code.

Now what?

Draw straw in tank

You very well could be right, where could I find more information on your sump setup?

I did also take the banjo bolt off the rail pressure relief valve, definitely fuel there, fuel ran down the sides of the valve when I cracked the banjo bolt loose. Does that indicate a possibly bad relief valve?

You don't have to put a sump in. You could replace the draw straw with a bigger aftermarket one- but I went with the sump. Just google diesel sump, there are a couple of different styles. I went with the xtreme diesel performance model. ( old style- I think they just updated theirs) I dropped my tank to install because I wanted to see the condition of my tank inside,etc after ten years- it was clean!! You don't have to drop the tank to install the diesel sump. Took me about two hours to drop the tank , install the sump and reinstall without a lift. Like I stated before- I fought this code for over two years- I replaced a lot of parts- talked to a lot of diesel professionals who are on this forum and other cummins forums. Had a lot of tests done,etc. on a whim, I said screw it, let's try a diesel sump. Solved my issues with po148! Two years this month I installed the sump- never had the code come back- just a suggestion- it solved my problem.

I went ahead and tapped the banjo on the rail relief valve, plugged it with a set screw. Same symptoms. Truck will seemingly run fine for a mile or so and then completely loose power. Will sit and idle in the yard all day long.

What were your symptoms leading to you installing the sump besides the code?
My truck is I drivable as it is. Only code it's throwing is the p0148

Lost of power when driving,dead pedal. Sometimes the truck would die and sometimes it would not. If it did stall. Truck would run fine after restarting until it happened again . That could be one day later or days later. It then could happen once a day (loss of power) or several times in one day. This went on for two years!!!

So after abandoning this project for ages and driving a Ford gasser, I rigged up a pressure gauhe to the filter housing drain. I found that according to this method I have only 3 lbs of fuel pressure with the engine off and the lift pump running and virtually no pressure with the engine running so it looks like my lift pump is shot, assuming this is an accurate way to measure fuel pressure? I'm assuming it would be, the filter drain should be under the same amount of pressure as the rest of the system.

So I ordered a new lift pump.