Printable View
Yes, the PPE is a loader and is not physically connected except to load a tune. I had the ECM flashed at the dealer and the PPE was never reconnected after that, so that was not a factor. Currently running stock tune with nothing plugged in and it is so very slow...
Was the PPE program unloaded, and returned to stock programming, BEFORE the PCM was flashed by the dealer? In any case, I suggest finding someone in your area with a similar truck that has a completely stock PCM, and swap it in.
Still, the problem points back to fueling anomalies that aren't causing the PCM to complain. A significant power loss should cause some data discrepancies, and DTC's. That is, unless the PCM does not interpret the data as being outside acceptable limits, or the limits are artificially adjusted, such as is commonly done with many programmers and power modules.
Best I can say is I've seen it before. Texas truck as I recall. In for head gaskets came back a turd. Never the same. Had to use an Edge Juice on 90HP to even feel like stock. I believe the end result was dumping the truck.Quote:
Originally Posted by Diesel Krazy
Whenever I see a LB7 truck that does not perform properly, but runs otherwise fine and everything checks out fine it always comes back to injectors.
This will NOT show on balance rates.
The ECM was put back to stock before reflash, I tried another stock ECM and even swapped out the FICM all with no change. Probably is plugged injectors which I considered early on, but would have thought that would have some other symptoms besides just low power. It sorta makes sense as it is totally non responsive stone cold when fuel is heavier and gets better as the fuel heats up and thins out. I may pull 1 or 2 injector lines to see if I can see any visible crud in them. I'm just afraid of opening a can of worms by doing that.
I would not recommend pulling the lines, without fully intending to replace them, or give them a proper cleaning (ultrasonic). Removal alone can, and does, cause the contamination. Re-installation doubles the chance of that.
If warmer/thinner fuel seems to improve power, try going to the extreme. Run a 50/50 mix of #2 and kerosene, with about 2% 2-cycle oil (replaces lost lubrication). This will make the fuel about as thin as you'd want to run. It will have a lower BTU content, but that should not be noticeable if more fuel is allowed.
Another thing to try:
Supply the fuel from a fuel can, bypassing the OEM fuel filter assy (use a high volume inline filter). Position the can at or above engine level for minimal suction required. This will eliminate nearly all of the OEM fuel system, if there is a restriction (or collapsed fuel line) causing the issue. Keep in mind, the fuel return circuit will not return to the can, so most of the fuel from the can will be returned to the tank. Ideally, a fuel container can be placed in the bed, with a long hose to the engine compartment, suspended at the door handle(s), and over the mirror.
Have you eliminated the possibility of fuel contamination (gasoline, or other fluid)? The fuel can test will do this, if you haven't. A 50%+ mix of gasoline could easily cause this power loss.
If I do pull the lines, I would likely use an ultrasonic cleaner to clean them after working out what I could manually first. I have run several tanks of fuel through it and it kind of liked B20 over the straight #2 Diesel. I had run some 2 stroke oil through it, Did injector clean with bottle feeding engine directly (that helped the injector balance greatly), Tried 1/2 bottle of ATF per tanks for 2 tanks full and it runs slightly better, but not affecting the main problem apparently. I did just pick up the test port adapter to monitor the vacuum on the fuel system. Dealer tech said it was showing 2Hg, but I think he only tested it at an idle. I want to try it while driving to see what happens. I'm hoping it's just an air leak causing the problem. I do appreciate the input...
The problem is you can't clean the lines in the hidden areas. The nut does not slide back to inspect and when you start to run the line down the nut grinds on the line well before the ball is seated.
If the injectors have debris in them you pretty much need to R&R them and then disassemble the nozzle and if you are lucky you can back flush them. Trick is not to not lose and small parts and to not get nozzle leaks and a crankcase full of diesel from removing the nozzles and reinstalling.
I wish the injectors were easy to test like the old style. I have a pop tester for them. Probably cost as much to have them cleaned and tested as buying replacements too. I'm pretty much stuck at this point as I am broke and broken... Can't work on much due to back problems and broke because I got laid off and my ex-wife is forcing me to pay her off or she will force me to sell my home... :-(
Anybody wanna buy a truck...
I have the same issue with LB7. Need help. Did you ever figure out problem??
Thanks
Posts #23 and #27
John,
Why can't you tear it down, and if the injectors are relatively low time, take them to a certified shop to inspect/test?
In the meantime, wire-wheel and spotlessly clean the injector lines (as clean or cleaner that new) before reassembly.
What's a new set of lines add to the cost?
Thanks, Jim
The trash is all inside the line nut area up the backside of the "ball" and impossible to clean. Once you start to spin the nut the trash grinds up and gravity takes it to the inlet bowl of the injector.
See pics here: http://www.kennedydiesel.com/docs/Du...0Corrosion.pdf
I don't know that we've seen any confirmation that the lines or heads were off for either of the trucks in question, but basically this and MAF signal errors are the keys assuming fuel supply checks out.
New set of lines is $600 OE and mandatory in my experience.
Mine has done exactly same. Except everything is new, including motor. Ran great for first 2k miles. Then something took a crap. Started throwing $$ at it and has not stoped. After engine rebuild, put pensacola injectors in. Every time i would talk to anyone and say that they would tell me its those injectors without even hearing anything else. Got to the point i had to put new injectors in again just so i had peace of mind the pensacola ones were out of my truck. Put new bosch in now but still same problems. Ficm is new, ecm is new, all sensors are new including maf. To save time only things on that are not new is fuel pressure sensor, alternator and a/c. Tuner is saying mass air flow is not working like it should. Put another new oem in and still saying its not ramping up like it should. New wcfab intake and cooler pipes. New 64mm ryans diesel service turbo.
Im lost at this point. Dont know what to do next. Ive put so much money in this truck its ridiculous. Wanted to make the truck new again instead of buying a new one but cant even enjoy it yet. Motor and all related now have 2500mi. Everyone always wants to jump to injectors but i will not do injectors again. And when i say new i mean all line, all seals n gaskets and even injector harnesses.
What the hell is the fix for this problem??
I promise to post my fix when found.
Did you have the tuning adjusted for the change in intake pipes? I'm assuming this is the one that the air filter is on as well.Quote:
Originally Posted by Jm1205