I'm working on a 92 3.1l v6 and using the definition file from tuner pro's website for the $88 code it has gm/sec instead of kpa when datalogging. Is there a formula for converting gm/sec? or is there something wrong with the definition file? Maybe i'm just missing something all together. The bin file i have azty has everything listed in terms of kpa for the map readings. Can anyone help me out? Thanks.

 

I just checked the definition file dated 12/27/03. It has the airflow in gms/sec and the MAP value in volts. The proper data stream bytes are being used. If you want the MAP in KPa it will need a different conversion.

Can use this one for direct convsersion of MAP ADC value to KPa:

KPa = (ADC * 0.369) + 10.415

RBob.

 

Thanks for that formula Bob. I was just helping a friend of my niece analyze a bad MAP sensor on his car. I was curious why it was always at "10". That forumla explains why.

 

Thanks Rbob, that answers my question. Now to add another equation to my list.

 

After finally getting the time to sit down and look at my datalogs. I see at one point the MAP voltage is at 4.33. So with the equation you posted I should plug in the value as so KPA=(4.33 * 0.369) + 10.415 which ends up being 12.01277. Looking at the azty bin file i see the lowest KPA being 20. Am i right in my thinking? Just trying to get the facts straight so i don't mess anything up. Thanks.

 

No, OK have that out of the way. The data stream output is in ADC counts, 0 -255. The conversion file (.ads?) is changing the ADC counts to volts.

The equation I gave is a conversion from ADC counts to KPa. You should be able to replace the ADC counts to volts equation to the one I gave.

If you want to convert from MAP volts to KPA, need to convert the volts to counts first, then to KPA. Or in one step:

KPa = ((MAPvolts / 0.01961) * 0.369) + 10.415

((4.33 / 0.01961) * 0.369) + 10.415 = 91.9 KPa

RBob.

 

Ah that clears up why i had such low readings. Thanks Rbob.