Factory trigger
Merc 190 2300
4cyl
distributed
VR sensor on crank
2 long metal pieces on flywheel (Vemstune scope shows good healthy signals). Is it hard to change to another VR sensor mounted a bit different angle (or away from the wheel, so bolts can be used), or with polarity inverted ?
- You should check to see if the raw signal (with proper scope) is not of the type found on the M103 engine here : MembersPage/MattiasSandgren/MercTrigger
- If they look alike, then the same trigger input modifications should be made to make it more robust, since the signal is not a true zero crossing signal.
Problem is that the negative pulses are placed to TDC.
- Changing falling<>rising doesnt seems to cure the problem.
- After redoing the test for some reason now it works fine.
- of course, since it's VR => only "rising" setting makes sense for the internal signal (and the LM1815 senses the falling edge)
- a possibly option would be to use an external VR=>HALL converter (possibly just an NPN inverter) with HALL sensor input (where edge selection does have an effect)
- or, alternatively use 20k pull to negative voltage, eg. -8V (instead of the default 18k VR pullup to +5V)
We can run 0 deg ignition at max or 45deg BTDC min.
Is this measurement or assumption ? The code has a hardly used feature
- MEASUREMENT WITH SCOPE,ON FRONT PULLEY
- with comment: // mostly for stock old GM trigger who has 10 degBTDC c004/6/8 trigger
- if ign_tdcdelay is 42 degrees (84 halfdegrees) or lower, and ignadv is higher than that, we allow timing from prev tooth.
- For more precise cranking you place trigger 15..10 BTDC of course.
- Cranking advance at TDC is suboptimal, of course.
- but did you try a very low ign_tdcdelay (eg. 0..5 degrees ?)
More details:
DC voltage = 207mV
Resistance of the sensor = 0,768 kOhm
We used the c004 no camsync to get it work.
We also examined your config, there were a few validate problems, and strangely 5 primary injectors were configured. Modified config uploaded:
http://vems.hu/files/MembersPage/NanassyPeter/Merc/
Peter, compare trigger to 6 cyl M103 engine : MembersPage/MattiasSandgren/MercTrigger
//Mattias
Thanks Mattias!
Thanks for all the instant help!Great support!
///pnanassy