[akotten]

I'm having some trouble with my fuel trims on 91 with very conservative settings. They easily max to 34% with only 13.5psi of boost. I'm FBO using the 7-24 maps. Any ideas? From what I've tried finding, it seems like some DME's just don't have the same fuel ceiling as others? I just replaced all spark plugs today (NGK 5992, .022 gap) and a coil on cyl1 that was causing a misfire. All is well with regards to that now. Also, is there a way to manually change the scaling for the AFR chart? Its stuck with 2.00 as the highest value for the y-axis, so the values aren't displayed. If you would like to see any other values displayed, just ask.


-Alex

[OpenFlash]

Log debug byte 4. That will tell you how much more fuel overhead you have though adjustments in the fuel tables. Easy to do once you know that info.

[akotten]

Originally Posted by shiv@vishnu

Log debug byte 4. That will tell you how much more fuel overhead you have though adjustments in the fuel tables. Easy to do once you know that info.

How about now?

[OpenFlash]

Yep.. No more overhead in there. You can drop boost a bit in the low/midrange to restore lower fuel trims. Or you can flash the dme to raise the dme boost settings so that it delivers for fuel. There may be an expensive at-home method to do this (and more!) soon enough.

[akotten]

Originally Posted by shiv@vishnu

Yep.. No more overhead in there. You can drop boost a bit in the low/midrange to restore lower fuel trims. Or you can flash the dme to raise the dme boost settings so that it delivers for fuel. There may be an expensive at-home method to do this (and more!) soon enough.

I'm a resourceful engineer.....challenge accepted. More details via PM? I won't be able to send it out until at LEAST the middle of May

[marconi118]

I have exactly the sale problem!!!!

05/2007e92 europe with original pre 29.2 DME program, maxing out trims between 2500 and 3500 rpm going over 12PSI, running procede 2.5 LE

This seems really related to DME mapping?

6 month ago Vishnu (robin) diagnosed failing injectors, but how can it be 6 injectors failing at the same time?

Now is it true that pre 29.2 programs have less room for fueling?

Any solution without sending the DME? Interested in flashing at home, or is it possible to rise (in the procede map) the fuel pressure in that RPM range to supplement more fuel?
What about coding the injectors with 30% less flow?

[marconi118]

What is debug byte 4?

The low or high fuel pressure?

[Jeller]

Originally Posted by marconi118

What is debug byte 4?

The low or high fuel pressure?

LPFP Voltage

[marconi118]

LPFP voltage of the pressure sensor or the voltage to hoe pump itself via the power module?

is it a shortcoming of the LPFP?

[OpenFlash]

Debug Byte 4 is the HPFP voltage output (from Procede to DME) signal. The lower you make it, the more the DME will compensate (increase injector pulse-width) for what it believes to be low fuel pressure condition. The catch is, if you reduce this signal too much (say below 1.5v), a fuel pressure code will be triggered. There is definitely some variance in respect to fuel system capacity between different cars. This has largely to do with variance in injector calibration, HPFP and LPFP capacity.

Shiv

[akotten]

Originally Posted by shiv@vishnu

Debug Byte 4 is the HPFP voltage output (from Procede to DME) signal. The lower you make it, the more the DME will compensate (increase injector pulse-width) for what it believes to be low fuel pressure condition. The catch is, if you reduce this signal too much (say below 1.5v), a fuel pressure code will be triggered. There is definitely some variance in respect to fuel system capacity between different cars. This has largely to do with variance in injector calibration, HPFP and LPFP capacity.

Shiv

Is there a way to fix the scaling on the AFR chart in my logs?

[marconi118]

Originally Posted by shiv@vishnu

Debug Byte 4 is the HPFP voltage output (from Procede to DME) signal. The lower you make it, the more the DME will compensate (increase injector pulse-width) for what it believes to be low fuel pressure condition. The catch is, if you reduce this signal too much (say below 1.5v), a fuel pressure code will be triggered. There is definitely some variance in respect to fuel system capacity between different cars. This has largely to do with variance in injector calibration, HPFP and LPFP capacity.

Shiv

What is the solution without flashing the DME?

Is my HPFP limiting it? it is new type 170
Are the old 2007 injectors causing it?
Why only some rare cars have this problem?

[chiefsotos]

Same problem to me with procede aggressive maps.
I am really interesting for a dme upgrade at home, without sendind it to Vishnu(i thought that will be availiable as has been said before some months).
the solution for now is to run autotuning maps which are limp free!!

[akotten]

Originally Posted by chiefsotos

Same problem to me with procede aggressive maps.
I am really interesting for a dme upgrade at home, without sendind it to Vishnu(i thought that will be availiable as has been said before some months).
the solution for now is to run autotuning maps which are limp free!!

These logs are on the 7-24 autotuning maps. I never get limp modes. In fact, the car feels great. But you can see the awful timing drop outs and maxed fuel trims.

[scottp999]

Originally Posted by chiefsotos

Same problem to me with procede aggressive maps.
I am really interesting for a dme upgrade at home, without sendind it to Vishnu(i thought that will be availiable as has been said before some months).

Hoping Shiv gets out a home flashing solution soon, maybe from that open source project he is involved in.

[OpenFlash]

Originally Posted by akotten

Is there a way to fix the scaling on the AFR chart in my logs?

Yes, very simple. Just click on the datalog channel in the bottom left window of the viewing software. Type letter "P" and you can adjust your scaling however you want. Or you can click on "auto scale" and the software will do it for you. Somewhere along the road, you must have changed the scaling manually without realizing it.

[OpenFlash]

Originally Posted by marconi118

What is the solution without flashing the DME?

Is my HPFP limiting it? it is new type 170
Are the old 2007 injectors causing it?
Why only some rare cars have this problem?

It's hard to say definitively what is causing it in any one car. Sometimes it is the LPFP not providing full pressure to the HPFP. Sometimes it's the HPFP. Sometimes it even the fuel formulation (higher ethanol content). Once you are at the point where debug byte 4 is below 1.5v, there isn't much more you can do other than flash for higher fuel limits which solves the issue completely.

Shiv

[akotten]

Originally Posted by shiv@vishnu

Yes, very simple. Just click on the datalog channel in the bottom left window of the viewing software. Type letter "P" and you can adjust your scaling however you want. Or you can click on "auto scale" and the software will do it for you. Somewhere along the road, you must have changed the scaling manually without realizing it.

Got it. Too easy. Thanks!

[badass335]

i'm definitely interested the home flash. Coming from Canada, shipping is a pain in the ass! As soon as I get my car back, i'm going to try to log it again to see what my car is doing. I need a fuel map flash to get things under control.