M104...what tells the ignition module to fire?
 

basically, what takes the place of the distributor? what tells the computer to fire and where? i would assume a crank position sensor... does the m104 have one?

On a 1993 & later version the crank sensor sends the signal for ignition operation.

thanks! will go from there. :)

bw... any idea what signal it sends? square wave something or other?

AC voltage (sine wave)

thanks for the info! i'll need to convert that signal somehow to make it work with megasquirt. :)

Switch to a trigger wheel on the front. The flywheel trigger (unless you have a very late model m104) only has three 'teeth' and doesn't provide that great of resolution as far as crank location.

what would you recommend? hall type? so i basically have to mount a trigger wheel at the front? how do i go about doing this?

Talk to Pumpish at TurboBandit (Turbobandit.com or mercedes@turbobandit.com)

He does full MS for Mercedes so he can get you trigger wheels and sensor mounts for M10x engines.

it's in german... does he speak english? :)

Yes, just email him.

And it's swedish :rolleyes:

oh ok swedish... hehe

what about the cam sensor... what kind of sensor is it? hall type? what signal does it send out?

IIRC it only has one sensor, and that's the TDC sensor. Basically it just tells the computer when it's at #1 TDC and firing.

I have a 1992 300CE with an M104 and my crank sensor is removed since it was broken and was only a plug-in for a test device. So, my question; How does the ignition module know when to fire? Is it also from a sine wave? And where does it get this sine wave? Maybe the cam sensor?

Just wondering. Thanks!

There are some graphs at the bottom of this page;
http://www.startekinfo.com/manual/volumes/e2/1_1/m24.jsp

br,
syljua