desired rail only 12K ?

MAP sensor!!

It worked!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I went home for lunch and loaded the MAP bypass tune from Les. MAP sensor will be here Monday. Thanks to all who helped out!!:woohoo:
 
Not the MAP sensor

Well I jumped the gun. After tuning around the sensor and the truck moving I assumend it was the MAP sensor. I received the a new MAP and IAT sensor on Monday. I flashed the truck back to stock and back to dead pedal and no power.

After some serious adjustments to the tune I have it driving a little better then a stock tune. The problem is the amount of fuel I am commanding. At 2800rpms160mm3 fuel, 3800us, and 30k (26K actual) of rail psi I am at 34lbs of boost 1100egt at 100mph MAX. That is like H&S amounts of fuel! I should be at warp speed or melted down! No smoke and no codes.

I have attached a log, it is a big file because I took it on the express way and opened it up a few times.

Thanks in advance.
 

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Thoughts???

Any ideas, APPS, FPS, ECM, CP3 ? Very difficult to diagnose without trouble codes. Can a dealership test an ECM or do they just scan it for codes?
 
Nothing? Should I start a new thread on this with the latest issues?
 
Engine temp read-40c the whole time? Doesn't most tuning stock or otherwise have a provision to limit power until engine temps are high enough to prevent damage?
 
I will check the wires when I get back to OK, I have been out of state for the last month. I don't think it is the MAP because I tuned around it and that got rid of the dead pedal. The log shows I am getting plenty of fuel, but the truck acts like it is not getting enough. I programed crazy amounts of rail psi and pulse width just to get it to run like a stock tune. I have NO smoke and low egts. I will do some more testing when I get back next week. Thanks.
 
Any luck?

It was mentioned earlier in the thread that a WOT run was only showing a 55% engine load

That right there is a red flag, and exactly why the tune is only commanding (and meeting) a 12k rail pressure. the ECM doesnt 'see' the engine load and fuels according to the tune and what the ECM 'sees'

At this point, the ECM sees your foot is flat on the floor, its only calculating a 55% load and is fueling accordingly. Basically exactly what you would get if you had the engine powering a golf cart...

So, do we have a load calculation error, or...?

One fun thing to try, have you got a lockup switch? might be fun to try a little pull with the TC locked and see what you get for a calculated load. maybe your TC has taken a crap on you... (once again, if your just sloshing oil in the TC instead of loading up the engine, your in the same boat)
 
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Will a TQ converter make noise when it is slipping, will it cause a dead pedal from a stop, and will it throw a code?

I have not figured it out yet. I sent the injectors out for testing to eliminate that part of the equation. I actually have it to where it is drivable by commanding crazy amounts of fuel. I am just worried if it is an intermittent electrical problem and it "fixes itself" I will melt the motor down.

So far I have changed the IAT, MAP, APPS, and RPS. If the injectors come back good about the only thing left is the CP3 and ECM. I don't think it is the CP3 because actual and desired rail psi are the same up to 26K. I don't believe its the ECM because I have no codes. According to the log the tune is doing as commanded, but the truck is not responding how it should, thanks.
 
Its definitely a weird one...

TC's can fail many ways, may or may not make noise, and wouldnt set any codes. definitely wouldnt cause the dead pedal

but dont always throw all your eggs in one basket, if your trying to diagnose something like this when your looking at the picture as a whole, you may end up overlooking something because a couple symptoms dont relate to the root cause. Dont count on the ECM spitting out a code, codes only mean the ECM was programmed to see the fault, its not the 'end all be all' of diagnostics :)

I doubt youve got an injector issue, your meeting desired rail pressure so they arent leaking, and your not spiking the rail, so they arent plugged full of crap...

im still leaning back towards why the ecm is not calculating engine load correctly. (dont have EFI on my work comp, so i couldnt see your log, just going by what was posted earlier)

A dead pedal, or in this case, it may not be a dead pedal, could be caused by engine load calculation error. Again, the ECM 'sees' your foot is on the floor, the ECM 'sees' their is a low engine load, thus the ECM doesnt go and fuel it to the moon

If the ECM is getting a true low engine load calc, and your at WOT, if it were to go to full fuel it would overspeed and spit its guts out in your driveway LOL But, in that same scenario, even with the engine unloaded, a snap throttle test should show a spike in engine load for a brief second until the engine picked up some momentum (then engine load would drop as would fueling)

Just for kicks, i'd check ECM pins 33/37/22 which are your +5v to the sensors and APPS, as well as 47/38/23 which are the ground. and triple check the ecm, engine and battery grounds. these things can do weird chit with a sketchy ground...
 
Once the injectors get back I will check the grounds again and also the pins you mentioned. If I unplug any of the sensors the truck WILL throw a code. Plug them back in and clear the codes no more codes. It takes twice as much pulse width and fuel psi to get the truck to do what it should normally. Thank goodness I have another ride until I get this fixed, thanks.
 
injectors

Problem solved, it was the injectors.

Lesson learned, never clean injector tips with a wire wheel:doh:

I want to thank BD diesel for helping me diagnose the problem, great customer service and great price on testing/repairing my injectors.

I also want to thank 2007 5.9 for help eliminating the tune as an issue.
 
There should be a list of good threads like this that have a good description of the problem and the solution that was found.
Congrats on getting it figured out
 
i was definitely scratching my head the entire time thinking...



this just goes to tell you that the entire time you KNEW it was electrical it was infact mechanical.
 
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