MoTeC Global Forum

I have a Motec M48 and Porsche 928 that uses a Bosch mag sensor on the 60-2 flywheel and a Bosch hall sensor on the cam. The cam sensor 'sees' one opening in the metal disk.
What rEF mode is it?
Any ideas or recources would be much appreciated, I seem to be ready to start the car on the weekend with Motec closed and am desperate.

Well, I've tried various ref modes even outside of the obvious 71-74 ones and it doesn't appear to be a matter of merely selecting the proper one.
Every attempt (71-74) yields the same result: With a timing gun on #1 there's a spark at 20° AND also 180° at 200. Sparks stop after a few revolutions with a sync error.
Could this be because of the sync being too close to TDC and/or the ref missing teeth? The sync signal starts at about 90° BTDC and ceases at 10° ATDC. Physically moving that sync trigger wheel is not a practical option.

I have a turbo 968 and need to set up ref sync mode - 60-2 wheel on ref
and hall effect for sync -how do i set it parmeter on computer ? for TDC :

You are using the correct Ref/sync mode and I would expect the triggers to work in their standard position. TO determine the triggering edges you really need to look at the trigger inputs on a scope otherwise you could pick the wrong edges which could give you problems further down the track when you are tuning. Also check that you have the other parameters set upo correctly (number of cylindrs, number of coils etc and that you have the ref and sync inputs wired to the corect pins (Ref Mag to pin 6 and Sync Hall to pin 7). Finally make sure that the engine is cranking over at a consistant speed. It is a good idea to remove the spark plugs and check the CRIP with the engine cranking over with them removed.

Hi Ross.
I'm still plaqued by the same behaviour even after tracking down basic mistakes. Please review my setup.

The setup:
M48 (all options) ign1 going to IEX
IEX to 8 individual Bosch ignitors and then 8 pencil coils.
60-2 mag sensor on the crank (crip=61)
Hall on the cam, solid disc with one opening (signal 90 BTDC to 10 ATDC)
Testing being done with plugs removed, #1 plug strapped down with a strobe gun in place.

The issue:
During cranking the timing mark can be seen and is where it should be at about 20° BTDC BUT a strobe appears also 180° from that as well.
Sparks stop after a few cycles with the "sync error".
All I've tried doesn't change that behaviour.

I feel that 73 is the likely desired mode, attatched are tests of the same sensors and engine on a friends car. The behaviour is also present with modes 71, 72 and 74.

Logging shows rpms (138 iirc?) and a clear sync event.

UPDATE
Umm... the ign type was incorrect for the IEX (1 instead of 100). I now get proper sparking although it still shows a sync error.

The car runs but I'd still like to hear some opinions on the above waveform and whether the mag and hall should be rising or falling, especially the hall because of it's unique trait of the trigger wheel's opening effectively making one really long 'tooth'. Would it be best to use 'falling' edge so as to avoid the rising one that's near TDC? Am I thinking correctly about what's seen above?

Use falling edge for the ref and rising edge for the sync. The sync edge ideally needs to occur between 110 degrees and 240 degrees before the index tooth(the first tooth after the missing teeth), your rising edge is closer to this than the falling edge is.

Hi Ross,

My situation is like this case.

I fit M800 on Citroen Xantia 16V engine.

It is also 60-2 missing mag ref and one pulse hall Sync.

My capture is here.



Ref / Sync setting ,

Mode 7
CRT 60
Tooth Ratio 50
CRIP 117
REF Mag, fall, 0
SYNC hall, fall, 0

I can see the timing degree is 0 when I use test advance which been set to 0.

But the error sync signal and no sync was appeared.

Please help me to solve this problem.

Thank you so much.

Marc
MSD IGNITION TAIWAN Dealer

Check your ref and sync filter levels, you can use the values described in the help file. It looks like the enmgine is not cranking over very evenly, try cranking the engine without any spark plugs fitted and see if it syncs up ok.

Also remember that any errors will remain present unless you manually re-set them. It is quite common to get some errors as the engine starts to crank over but that clear straight away. Does this engine run?