Engine Logging problem...

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hobieboy
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Engine Logging problem...

Post by hobieboy »

I posted a related question in MS3 General but get no help (http://www.msextra.com/forums/viewtopic ... 31&t=58540) so am posting here for a more specific Megalogviewer question -

In the Engine Logging+MAP log file (you can find full data log & MS file in the other post), each section of records is separated by a Mark record.
What does the Mark represent?

Am wondering if MS3 will stop-then-start logging every time it writes one of these Marks; which explains why I am seeing so many missing / wrong Ignition & Injection pulses? (e.g. at record 255/Mark 0 point, Spk B,C,D are missing. At record 1026 / Mark 3 point, Spk B fires but there is no Spk B and Spk B pulse width is much shorter than usual. On the Inj pulse, Inj B, C & D are also not there when Spk B, C, D were seen).

I am chasing a misfire problem (at high boost only) so want to use Engine Logging to determine where the problem is. Right now, I am not sure if I can trust/use Engine Logging...

thanks!
LT401Vette
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Re: Engine Logging problem...

Post by LT401Vette »

Am wondering if MS3 will stop-then-start logging every time it writes one of these Marks;
Yes... The high speed loggers are captured quite differently as they are generally used for capturing data too fast to send over serial.

Unlike a standard data log that streams the data as you go. When using a high speed logger, the data is written to RAM in the ECU, it writes until the data page is full, then tells TS it is ready to be read, TS reads it, the firmware starts logging again. So there is a pause in logging each time the page is full and waiting to be / being read.

MLV renders this with a red line so you can see where the data gaps are.
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hobieboy
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Location: Up North

Re: Engine Logging problem...

Post by hobieboy »

Thanks for the clear explanation Phil...

Think this explained clearly why I have the missing pulses even at idle.

thanks!
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