Possible boost leak

[mkinnunen]

Could somebody please review this log for anything obvious. I am getting 9 MPG towing #13000 fifth wheel. No smoke, no engine codes just horrible mileage. 60mph-70mph towing in 5th or 6th doesn

[Tommy ashley]

What file app can I get to open these files on iphone

[ScarabEpic22]

What file app can I get to open these files on iphone

None, EFILive is Windows only. You can do some minor switching of DSP tunes on certain applications on Android only.

[GMC-2002-Dmax]

Could somebody please review this log for anything obvious. I am getting 9 MPG towing #13000 fifth wheel. No smoke, no engine codes just horrible mileage. 60mph-70mph towing in 5th or 6th doesn

That is expected mileage towing depending on speed and shape/type of trailer.

9-12 mpg is all you can expect towing that weight.

[mkinnunen]

I would like 12 MPG, since i can expect that, what should i do to improve what i am getting?

[GMC-2002-Dmax]

I would like 12 MPG, since i can expect that, what should i do to improve what i am getting?

Driver slower, speed kills MPG, just because you expect or want a given fuel mileage does not mean you can have it.

Trailer design, towing while a head wind fights you, towing grades.........be happy its not a gasser.

I have had a Duramax since 2002, the best I got towing my 10K 24/ft V-Nose was 11.6, it got as bad as 9.9 in certain conditions.

Keep it at 62-65 mph, anything over that..........kiss fuel mileage BYE, BYE

[mkinnunen]

But even at 60, I get 9 mpg, so again your "advise" of keeping between 62-65 holds no new usable information, My gasser gets 6-9 mpg pulling the same trailer. Someday i'll find what is the issue and i will report back, or if after all the tuning options have been explored and all the hard parts have been replaced i'll concede that my truck just gets 9 mpg and it is what it is.

Thanks everybody for your input.

[Bdirtymax]

Looking at the log, it seems you have low air flow across your MAF for some reason. You have a max of 47.83 lb/min at 3229 RPM. Should be 60+ lb/min from my personal experience. The boost is following desired within about 1psi. Not sure why your vanes are closed so much most of the time. It's averaging over 70% throughout the log. Is this a tune you are working on yourself?

[mkinnunen]

Bdirtymax, thank you for reviewing the log, yes I am working on this tune myself, the only changes from stock at the time of that log was EGR block and speedometer adjustment although I have made many changes since then. I also was concerned about the MAF flow (in a different thread), Cleaned it and had the opportunity to travel to phoenix where the flow seemed normal (about 20% difference) so I believe The low MAF is from elevation (5500ft). I had only checked MAF flow at idle, that may have been a mistake.

Thank you,
Michael

[Bdirtymax]

Bdirtymax, thank you for reviewing the log, yes I am working on this tune myself, the only changes from stock at the time of that log was EGR block and speedometer adjustment although I have made many changes since then. I also was concerned about the MAF flow (in a different thread), Cleaned it and had the opportunity to travel to phoenix where the flow seemed normal (about 20% difference) so I believe The low MAF is from elevation (5500ft). I had only checked MAF flow at idle, that may have been a mistake.

Thank you,
Michael

Yes the higher altitude would affect your MAF readings. Without seeing more tune data (more pids) or the tune itself it could be anything. It is still odd that it is commanding such high vane position all the time, even high altitude tables don't run that high. The base transient table runs higher but not the entire table. I don't know if this is a single tune or dsp tune either. Fuel pressure looks ok but it could be timing, pulse or combination of.

[mkinnunen]

Here is my current tune file and most recent log file (unloaded going to work). I had knee surgery so no new logs recently.

22538
22539

Thank you,
Michael

[Bdirtymax]

Here is my current tune file and most recent log file (unloaded going to work). I had knee surgery so no new logs recently.

22538
22539

Thank you,
Michael

Sent you an email