[willholman]

Hi. Does anyone know what the tooth pattern is that the M117 crank sensor reads? I mean is is 36 minus 1 or 60 minus 2 etc? I ask because I'm considering converting one to EFi and need to spec an aftermarket ECU to suit. An Emerald, Omex, DTA or similar.

I know the sensor on the front damper just has one cutout but I'm wondering about the one that sits on the top of the bellhousing and, presumably, reads the flywheel.

 

[mclare]

It does read the flywheel.

 

[willholman]

Hi. Thanks. Yes – I know it reads the flywheel – what I need to know is what pattern it reads. Does, for instance, the flywheel have 36 marks (one for every degree of rotation) then one missing mark so the ECU knows where it is? This is a common system use by, amongst others, Ford. Other systems use 60 marks and have two marks missing so the ECU gets two reference points for every revolution of the flywheel. I ewas just hoping someone might know what system Merc used on the M117 engines so I can see whether an aftermarket ECU will read it.

 

[mclare]

There are 4 segments on the driver plate.

If you look at page 15.0713-540/13 "Testing Ignition Timing" (in the engine manual) you will see the diagram, and you will see CPS signal image.

These are off my old engine as I was building up my new engine:

 

[jonwhite99]

Only Gen 2 has a flywheel sensor

Hi,

Only Gen 2 has a flywheel sensor.

The Gen 1 cars have almost no electronics at all.

If you have a Gen 1 car I would suggest adding a 36-1 toothed wheel to the front of the Crank pulley if you Google 'ford edis megasquirt' there is plenty of info out there.

Good luck, and watch for leaking fuel lines as a fire kills a car (Do not ask)

 

[mclare]

I only speak to Gen II issues. I know little about Gen I.

 

[willholman]

Thanks. I didn't realise it was just four segments on the flywheel. Looks like I'll have to add a Ford 36-1 wheel to the crank pulley.

 

[mclare]

You are welcome. Yeah, that will probably give you the best resolution at 10 degrees.

 

[V12StealthHunter]

Found on the net.
36-1 Trigger Wheel Custom EFI VEMS Megasquirt Megajolt Mercedes M116 M117 95 mm | eBay

Passed for Pulley from motor M116 M117 Mercedes as of 1985, or other custom EFI project.
Inner Diameter 95 mm.
Outer Diameter 125 mm.
Thickness 6 mm.

 

[willholman]

That looks spot on - thanks for the heads-up. I wonder whether he sells that bracket too?