MicroSquirt.com read only forum (Jan.15,2018)

Hello,

My configuration:
Porsche 944 2.5l NA, MegasquirtII DualSpark, stock sensor (130-0 wheel and 1 tooth crank wheel), Second Input circuit LM1815 based, second output, Dual Coil wasted spark Ignition, V2.89 code. That work fine since few months.

My Problem : I try to use a wireless Bluetooth ...

Hello,

Oups, I forget to explain that I switched my probe in X10 for the VRin signal. The value for the green signal has to be multiplied by 10. So the tach pulse is 4v p-p and the noise around 200 mV p-p.
The mode 1 of LM1815, is adaptative. Input Arming Threshold is depending of the amplitude of ...

I fixed my problem!!!
Look at the scope of VRin and VRout signal of the crank sensor (input 2) during cranking : A lot of false triggers.
The VR board, i add, for the crank sensor is based on LM1815*. For this circuit, it's possible to choose different modes and different 'input arming threshold ...

Last Update : Advance mesure with strobe during Cranking is 41° (my setpoint is 8°). I just do the test one time.
I Hope that this information will be helpful.

Patrick

Ok, i made a mistake with my scope AC vs DC!
Finally the 2 VR signals are clean, and i can not see any difference when the advance is good or when there is an offset.
I confirm now, the problem, a lot of time : I start the motor, MT gauge and strobe are not agree. The offset is constant and stable ...

Thanks again for your help.
The answers to your questions:
-I always have used ‘calculated advance’.
-My cranking RPM is around 300 rpm, my idle is @850 rpm.
-When MT gauge and strobe measurement are not agree, it's true for all RPM .I do the test by setting all the spark table cells to 8°. I ...

Hello again,

I have a new amazing issue with my Porsche 944 Megasquirted in dual spark mode. Sometimes an offset of around -30° is added to the advance read on megatune. Example, at idle, the advance read on Megatune gauge, is 8° but the advance read with the strobo is 39°. When i do a 'burn to ...

Thanks for you analysis, i plan to buy a 2F audio capa in the next day to finalize my installation.

But, i think i fixed my issue. I had tach loss at always fixed rpm mostly at 1700, 3400rpm. Signal measurement with oscilloscope shows me that the crank sensor has the bad polarity. The logic output ...

Merci beaucoup!
Thanks!!
Explanation was clear and now...
It works fine with Trig. Offset = -30° (before -301.5) and Delay Teeth = 30 (before 0) ...No more dwell shrink. See attachements.
My next problem is the tach loss you can see on data logging. I will try to fix it by myself with the forum ...

Hello,

I ended few days ago the megasquirtII conversion of a 84' 944na Porsche with the help of the information found in this excellent forum (thanks Jlturpin, M. Grippo, etc...).
A quick summary of my configuration: To re-use the 2 stock trigger sensors (130 tooth crank wheel without missing teeth ...