Members Page/Marcell Gal/Power And Traction/Input Trigger

MembersPage/MarcellGal/PowerAndTraction/InputTrigger (2007-05-01 21:07:36)

Trigger related subpage of MembersPage/MarcellGal/PowerAndTraction

There is still some uncertainty about which sensor position is which.

They mounted the engine (apparently properly ;-) but ... the 2 sensors were in a box. The 2 sensors

look almost identical (one has grey boot, the other has black)
with same pinout,
measure 1001 and 985 Ohm, respectively
has 3-pin AMP-style male connectors.
- using a DVM in DC mode, and a wrench, we checked in 1 minute that the mid-pin must be GND for proper polarity (and the pin at the side must be the signal). The proper polarity (with LM1815 that senses falling edge) means signal is positive when wrench gets closer to sensor and negative when wrench comes away
- Of course, in the factory wiring the GND (which is shared between the sensors, and probably with other sensors) is the other, so I need to swap the 2 wires in the harness to reverse polarity . This confirms what Miska documented earlier.

the holes at the very top of the clutch housing, see [pic15] and [pic14] look like those for VR sensor (maybe not: hard to tell with engine mounted). Not sure what this can be good for, though....
See [pic17] for the 2 good candidates for crank135 and crankhome: both on the right side of the engine, close to each other.
- the front sensor is the crankhome. This sensor closer to the sky, it sits deeper in the housing, see [SJM pages]

We might have to scope it anyway, to verify crankhome polarity and HALL window position.

Found some metric (M6?) screws, used a washer and an extra female to make it proper length, and mounted sensors in the 2 holes close to each other.

Teppo said:

grey one reads flywheel teeth
black reads the pin behind the flywheel

That is, with normal mounting. I will have to check (and document) if I followed the standard (colors: no other difference between sensors), or got it with colors swapped.

Cam-HALL sensor

There are 2(-3) possible cam-HALL setups, with exactly the same function.

http://www.sjmautotechnik.com/trouble_shooting/20vhall.html
- timing belt sprocket, at the front-end of the camshaft
- inside the distributer
  - dummy distributer
  - real distributer (that's what I have)

I found that ...

I see the window (I have a one window shutter-wheel mounted). A 5-window wheel would be easier to setup, because a random position is likely good there, while a random position is likely bad with the one-(small-)window wheel.
after unclamping the M13 screw, I can move the HALL sensor (moves together with the "Bosch" housing)
DVM measurement: the sensor gets 5.08V
(when sensor disconnected): I can pull the HALL signal to GND with a small wire (and measure EC36-pin13 go from 3.97V to 0V)
but the sensor will not pull to GND

Conclusion: my HALL sensor is bad. Maybe I patch the code to allow running without HALL (but I expect bad starting with disconnected HALL, or with HALL that fails to constant open: every 2nd attempt on average). This would be similar to the factory motronic setup, which continues to run without HALL sensor. But with a certain configuration, we could also start up the engine (with 50% chance).

Although I have small HALL sensor, and 1GT101 sensor too, it seems difficult to mount it in a sane way (either on front side wheel or inside distributer). Had the front-side wheel have 5 (or 7 or any odd number would work) spokes, instead of 6, that would make it easier to watch those with a 1GT101 HALL sensor.

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