Some weird PIDs?

[Dinosgt]

Bought the Ngauge several months ago, and I started datalogging. While I get some of the PIDs and why they are relevant, some I don't. Can someone enlighten me on what the following PIDs mean and what values I am looking for?

ipsibr_IN_ppm (?)
MAF_in_lbm_per_min - what's a good vs bad value?
LOAD_as_a_fraction (?)
PPS-APP1 (?)
tq_source_pid (?)
MAF_Hz (?) What values make sense?
AFR1, AFR2 - I presume these should ideally show a "1", and go low when rich - how can you figure out real AFR from these values? (They are currently shown around 1.0)
TFT11, STFT21 (?)
LTFT11, LTFT21 (?)
FRP_relative_in_PS (?)
FRP_ACT (?)
TQ_DD_LIMIT (?)

I apologize - I scoured the net and cant find these. If anyone has a link let me know...

THANKS

 

[decipha]

ipsibr is the idle air integrator, its the amount of air the ecu has to add to reach idle, since your dbw it should be 0

Maf is just the airmass flow from the maf sensor

Load is fords VE

Pps may be the power steering transducer or the throttle commanded

Tq source is a bitmask flag for the currently active tq limiting routine

Maf hertz is the actual maf frequency being read from the maf sensor, thats the 2nd most important variable in a mass air ecu only second to the crank trigger

Afr1 and 2 are the wideband readings in LAMBDA 1.000 = stoich, forget about afr and use lambda youll happier, but *14.1 = e10 afr, if your running e85 *9.1 = afr, if your running pure gas *14.64 = afr

Ltff is KAMRF known as the long term fuel trim

Stft is LAMBSE known as the short term fuel trim

Frp is probably fuel rail pressure delta and actual, tq dd could be throttle or the currently active torque limit

 

[Dinosgt]

Many thanks - I have asked a half dozen people what some of these meant, and you are the first to offer up some answers. THANKS!

Maf is just the airmass flow from the maf sensor

What values make sense? Am I looking for a pattern or absolute values? The numbers seem to range from 1 to 80.5 and follow rpm closely in steps

Load is fords VE

What is "VE"?

Tq source is a bitmask flag for the currently active tq limiting routine

Does this mean something like a traction control to limit torque? My values range from 0 to 13, but goes highest when the throttle is off and rpm low, returning to zero under full throttle.

Maf hertz is the actual maf frequency being read from the maf sensor, thats the 2nd most important variable in a mass air ecu only second to the crank trigger

What anomalies do I look for there? I read between 8 and 10 under WOT

Ltff is KAMRF known as the long term fuel trim


Should I be looking for a constant value of 1? I see it ranges of .99 to 1.04, but usually around 1 under full throttle

Stft is LAMBSE known as the short term fuel trim

How is this different than long term trim?


Frp is probably fuel rail pressure delta and actual

these values move between 45-50 under WOT, then spike to 70 once the throttle is released

tq dd could be throttle or the currently active torque limit

these are usually at zero, spike to 9 and stays there under WOT

Thanks again - I am sorry for such newbie questions, but I want to understand this stuff before I attempt to load a tune, so I can see what changes and its effect.

 

[15PSI]

Your MAF numbers are measured in Lbs per minute of airflow. Older MAFs translated the air mass into voltages, but newer MAFs employ A/D converters that digitize the voltage output (0-5V) into results the ECU will use in various lookup tables. The numbers will reflect the amount of air mass moving through the MAF based on your engines pumping capability and efficiency. These numbers will change dependent on modifications to your engine. VE is Volumetric Efficiency; the efficiency of the cylinder(s) to fill with air. As was stated, this is Fords 'Load'. VE will exceed 100% with boosted motors, and is normally less with NA motors. Having said that, highly tuned NA motors can exceed 100% - the new 5.2L flatplane engine supposedly has a VE of 110% (ie. It can pump more than 5.2 Liters of air because it benefits from pretty slick resonance tuning). To describe VE another less confusing way is it specifies an engines cylinder filling efficiency by how much AIR MASS enters the engine during the intake cycle compared to the amount of air mass the cylinder could theoretically hold. Dependent on your mods, the output frequency of the MAF could be exceeded by the engines air demands; the MAF would be pegged at it's highest measuring point and would have to be rescaled. LTFT refers to changes in STFT but averaged over a longer period of time. A negative fuel trim percentage indicates a taking away of fuel while a positive percentage indicates an adding of fuel. STFT is referenced by the 02 sensors (HEGOs on the newer Stangs). The numbers you mentioned for your LFTF are normal. If you use LiveLink GEN-II (SCT), look under 'TOOLS' then 'LIST'. You will find code lookup tables for TORQUE, ETC TORQUE and TORQUE DD. And honestly, I know just enough about the TORQUE codes, to know I shouldn't try to explain them. And. finally, try to always think in terms of LAMBDA. LAMBDA will be a value of '1' at Stoich for the type of fuel you are using. e.g. 14.64:1 AFR for pure gasoline would equal '1' Lambda. 11.5:1 AFR (100% Gasoline) would calculate a LAMBDA of .79 (11.5/14.64 = .785).