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View Full Version : LMM example of "something ain't right here"



killerbee
November 7th, 2009, 06:28 AM
I have taken a snapshot (highlighted white) of the area for discussion.

Foot is steady on the pedal, speed steady, essentially steady state 60 mph.

What I would expect to see, is Main1Q steady, with minor fluctuations in pulse and pressure. What I see is Main1Q all over the place, and pressure is steady as a rock. With my tables, if Main1Q was actually spiking like this, 23-33mm3, then my pressure should be all over the place as well. But it is steady, as predicted. Is there something wrong with MAIN1Q?

(sorry, there is no valid torque pid to use)

I am just not getting it. If you do, throw something in here.

http://forum.efilive.com/attachment.php?attachmentid=6579&d=1257618568

killerbee
November 7th, 2009, 07:08 AM
And FWIW, 66MPa of fuel pressure is 17-18 mm3 on my Pressure Tables. More mystery.

vortecfcar
November 8th, 2009, 09:43 AM
Is this vehicle running a new ECM, if so did you recalibrate the fuel injector flow rates on the truck?

killerbee
November 8th, 2009, 09:47 AM
no, stock ecm.

GMPX
November 9th, 2009, 05:56 PM
Michael, I need to do the post SEMA Email, PM, forum, business card catch up first, but your log is interesting indeed.

Cheers,
Ross

P.S - DSP6 ?

killerbee
November 10th, 2009, 12:43 AM
No worries. I have a lot on my plate this week also.

DSP6 is just a 2 pole version of dsp5. The second circuit can control a peripheral device with the 6th position, pos 5 and pos 6 using the same "factory maps" tuning. I did this so drug users had a reliable way to NOT use drugs with tunes that are not designed for them.

Note also, I have reversed the circuitry in the switch clock positioning, makes it more intuitive for the operator and the tuner to having increasing power with clockwise rotation, and keeps "factory maps" a good failsafe tune if the switch is pulled out or broken.

bballer182
November 10th, 2009, 02:05 PM
Michael, I need to do the post SEMA Email, PM, forum, business card catch up first, but your log is interesting indeed.

Cheers,
Ross

P.S - DSP6 ?

more like a 6 position DSP5 switch... I like the idea; very crafty for those who use drugs.

JoshH
November 10th, 2009, 06:35 PM
I just looked at an LMM log I have and I see something similar, but not nearly to the same degree. I see a 5 mm3 swing from highest to lowest.

killerbee
November 17th, 2009, 07:24 AM
Michael, I need to do the post SEMA Email, PM, forum, business card catch up first, but your log is interesting indeed.

Cheers,
Ross



another example. Main drops in half while pressure doubles. Pulse an Main appear related, but pressure is on its own. The question here is why main (pulse) is dropping at all. It should be increasing, like pressure is.

http://forum.efilive.com/attachment.php?attachmentid=6630&d=1258485837

Racehemi
November 17th, 2009, 11:18 AM
What is your actual rail pressure doing? Fueling is based on actual not desired fuel pressure.

What number did you come up with for your EQ calculation?

killerbee
November 17th, 2009, 01:39 PM
I believe it is tracking right with desired, based on other logs. I know what you mean. I will take a closer look.

killerbee
November 18th, 2009, 04:34 AM
They are tracking together.

But I have made a breakthrough. The log curves for des rail pressure mirror boost very closely. There is some relationship there. So in 6th gear, the rail pressure stays very low, while the pulse goes very big because actual pressure is being held down by the low boost level that are only possible in tall gears. Can't make the boost, therefore pressure remains down until a downshift occurs.

This is a very important thing to figure out if the LMM is ever to be refined with efilive.

side note: I increased B1059 in my trial/error learning curve. This table, when I changed it to large values, created a stall condition and rail pressure codes. I verified this by going back to the previous tune with the old values, and everything was fine. Reflashed with just this table changed, and it happened again. FWIW.

bballer182
November 18th, 2009, 03:10 PM
They are tracking together.

But I have made a breakthrough. The log curves for des rail pressure mirror boost very closely. There is some relationship there. So in 6th gear, the rail pressure stays very low, while the pulse goes very big because actual pressure is being held down by the low boost level that are only possible in tall gears. Can't make the boost, therefore pressure remains down until a downshift occurs.

This is a very important thing to figure out if the LMM is ever to be refined with efilive.

side note: I increased B1059 in my trial/error learning curve. This table, when I changed it to large values, created a stall condition and rail pressure codes. I verified this by going back to the previous tune with the old values, and everything was fine. Reflashed with just this table changed, and it happened again. FWIW.


I still don't know what to do with that tables either. So it sits in stock for for time being...

killerbee
November 18th, 2009, 05:13 PM
I did some more trials, the boost/fuel pressure dependency is not what I thought.