Scan9495: Free OBD1 scan app for 93/94/95 LT1
#288
re: Scan9495: Free OBD1 scan app for 93/94/95 LT1
With the program's .csv file saved in excel format, add columns next to the A/C pressure, and use Gary's formula (and the sensor calibration) to convert the pressure to voltage to lambda to A/F ratio.
Last edited by Injuneer; 06-23-2015 at 10:30 PM.
#289
re: Scan9495: Free OBD1 scan app for 93/94/95 LT1
Lol, Thats not going to happen. I can barely save and view a log file.....
#290
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re: Scan9495: Free OBD1 scan app for 93/94/95 LT1
Version 2.2.0 is posted. It changes the "RPM filtered" reading to "A/C pressure (volts)". Loading older version log files with this version will have the wrong readings for A/C pressure in volts. Conversely, loading new log files with an older app than 2.2.0 will have the wrong readings for RPM filtered, but I doubt if anyone was using it anyway.
FYI, as of a few versions back, all log files have the app's version number at the front of the file. But that number is not used by the app, so you will have to view it to see the version of the app that created the file.
FYI, as of a few versions back, all log files have the app's version number at the front of the file. But that number is not used by the app, so you will have to view it to see the version of the app that created the file.
#291
re: Scan9495: Free OBD1 scan app for 93/94/95 LT1
One of the first things I do in Excel when I get a log to review is "hide" the columns I'm not really interested in, including "RPM Variation %" and "Engine RPM Filtered".
#293
re: Scan9495: Free OBD1 scan app for 93/94/95 LT1
I think it deals with how many bits of resolution are used. The 8-bit format limits the display to 25 RPM increments = format for "Engine RPM Filtered" - the data log entries in this field are always in 25 RPM increments.
May be using the Opti high res pulses to interpolate inside the 25 RPM increments to get "Engine RPM" - displays in discrete RPM. Or it may be using an expanded 16-bit field. In Datamaster, the discrete RPM entry is labeled "RPM-16". Not sure though.
Gary may have more insight into this.
May be using the Opti high res pulses to interpolate inside the 25 RPM increments to get "Engine RPM" - displays in discrete RPM. Or it may be using an expanded 16-bit field. In Datamaster, the discrete RPM entry is labeled "RPM-16". Not sure though.
Gary may have more insight into this.
#295
re: Scan9495: Free OBD1 scan app for 93/94/95 LT1
Gary indicates it will work. I have looked at a lot of data logs, but have never used the system myself, because I really don't use the stock PCM any more for anything other than the speedometer and the IAC valve.
#296
re: Scan9495: Free OBD1 scan app for 93/94/95 LT1
I ordered my FTDI cable but when I cut it open today, I have no white wire. The pin out on the opposite end from the USB is black-brown-red-orange-yellow-green. What color should I be using in place of white? Thanks!
#299
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re: Scan9495: Free OBD1 scan app for 93/94/95 LT1
For others with the same or similar issues: If I remember correctly, in this case, you substitute the orange wire for the white one. The goal here is to jumper the TXD and RXD signals together and feed those to the car's data pin connector. If you have a signal diagram for an adapter (or markings on the circuit board), you may be able to figure out which wires to use.