I had (and I continue to have problems with tunerPro RT )
Please refer to this post:
https://www.thirdgen.org/techbb2/sho...ighlight=beppe

I tried Datamaster (I downloaded the software at TTS site with 20 datalog trial version).
It seems it works with my 90 corvette.
I have not started the engine yet (I have a little problem with the trans...) but with the Key On Engine Off I can see all data are ok and I can capture up to 6 or 7 data per second.
The strange thing is that with Tuner Pro Rt I have a MAP reading of 95,69 with KOEO and at the same time with Datamaster 100,60 Kpa.
Why?
Is the sofware that translate the ALDL flow in translated (calculated ) numbers?
The signal fron the ECM to the ALDL should be the same...
Maybe datamaster has a different calculation to translate this signal?
I'm at about 600 ft.
Someone else with this issue?
thanks
-Beppe-

 

The 100,60 KPA is probably correct. Check the ALDL definition file being used with TunerPro. The math in that needs to be checked.

RBob.

 

Are you referring to the factor used (0.392157)
with the Operation? Multiply([X*Factor]+offset)
I noticed that a factor of 0.41000 will be good to be in line with datamaster readings.
The difference is about 5 or 6%%...
So if my car idles at 25 kpa in Neutral
and idles at 34 kpa in Drive with the brake pedal applied
these figures will be about 26 or 27 in Neutral and 35 36 in drive..
All MAP value will be higher 5% more (a 60 MAP will be 63..)
Is there a way to know the right one? (TunerPro or Datamaster)
Thanks
-Beppe-

 

The $8D code outputs the MAP sensor ADC counts. This can be converted to a voltage by:

VOLTS = ADC * (5/255)


To convert from ADC counts to KPa I use:

KPa = ADC * 0.369 + 10.415

-or-

(KPa = ADC * 0,369 + 10,415)

To double check the whole thing can reduce the sea level air pressure by 600ft. The KOEO MAP reading should be very close to that.

Can also change the ALDL definition file for no math and read the MAP directly in ADC counts. Then do the conversion as above and check it.

RBob.

 

Thanks RBob,
Your formula for MAP value is good.
I changed the ADS file in tunerpro and now I have MAP value with more sense.
The tunerpro ads file (for 730) uses only the Factor without an offset value.
Your formula uses the offset value with a sligltly different lower factor.
I used your factor and your offset and now my KPa value are very good.
In effect I was searching a logic to see the DFCO logic.
Now with new MAP value I can see that the IBPW go to 0 just when the constant and tables related to DFCO says.
Since you formula uses an offset value now my lower KPa value are about 10Kpa greater .
It idles at about 43 kpa at 675 rpm with the car in drive
and idles at about 34 kpa at 775 rpm with the car in N.
These value are right for a supposed stock cam in my vette?

Another Q.:
If I see the main Spark table at a given RPM /Map value and I see my datalog file for these same RPM/Map value I can see that the advance used is much more lower.
example:
if the Spark table say 1200 rpm with 30 Kpa = 34.10 deg
in the datalog I have for 1200/30 about 21 or 22 deg of Spark Adv Rel. to TDC (no knock retard).
Maybe the formula for the spart advance is wrong too?
Is there aplace in the net where I can a find formulas?
Thanks and sorry for all the Questions..
-Beppe-

 

Could be (incorrect calc). Relative to TDC means the SA should be reported as is at the crank.

SA = N * 0.352

The $8D mask also outputs SA relative to the reference pulse. In this case the base timing needs to be added back in.

SA = N * 0.352 + base

Another item, at 1200 RPM, 30 KPa the ECM may think that the engine is still in idle mode. That is, vehicle not moving and TPS% below a small value.

Then with the RPM too high the ECM will pull timing out in order to bring the idle speed down.

RBob.

 

Thank you,
the caculation is right for Spark Adv Rel. to TDC (factor = 0.351563)
Yes the value I posted to 1200 rpm are most with 0% TPS with some MPH, but in this case maybe the "Spark adv. closed throttle" can play his role...
-Beppe-
P.S.
No one on this?:
I said:" It idles at about 43 kpa at 675 rpm with the car in DRIVE
and idles at about 34 kpa at 775 rpm with the car in NEUTRAL.
These value are right for a supposed stock cam in my vette?
-Beppe-