hi all..im using a turbo 500 twin in my bike,it uses a honda pickup triggering a four pin gm module,with another pickup from an audi triggering another gm module .these then trigger a msd mc1 box which then fires two coil in the cap coils .so wasted spark ,and 2 totally independant pickups modules and coils ,fixed timing .with one tooth on the crank trigger wheel .i can put on a wheel with lots of teeth and a gap .but what id like to know ,is can i put a mjlj in between the pickup and the msd and use the mj to trigger it ,with the output to cyl 1 to one trigger and the output to cyl 2 to another trigger on the msd box.so id have the multi toothed wheel ,with the honda pickup this goes to the mj that fires the msd with its coil trigger pulse?
is this a goer??
also whats the max rpm i can use ,this engine needs 12500 capability .
thanks for ploughing through this disjointed description!
robert
megajolt applicable?
Moderators: JeffC, rdoherty, stieg, brentp
Highly unlikely...
...although what you describe is kinda hard to understand I'm afraid 
Imagine the following as a left to right drawing of the components of a MJLJ system.
36-1 toothed wheel, which is sensed by a...
Ford VR sensor, which sends a modified sine wave to a...
Ford EDIS module, which sends a pulse train to the...
MJLJ, which sends synchronised pulses of certain lengths back to the...
Ford EDIS module, which fires the...
Wasted spark coil, which causes a spark in the...
Spark plugs
So you can't connect a MJLJ straight to a pickup, and the synchronised pulse coming out from a MJLJ are highly unlikely to trigger a MSD at the right time
See http://www.bgsoflex.com/mjl/mjl_edis_summary.html for a fairly technical description on how a MJLJ works...
Imagine the following as a left to right drawing of the components of a MJLJ system.
36-1 toothed wheel, which is sensed by a...
Ford VR sensor, which sends a modified sine wave to a...
Ford EDIS module, which sends a pulse train to the...
MJLJ, which sends synchronised pulses of certain lengths back to the...
Ford EDIS module, which fires the...
Wasted spark coil, which causes a spark in the...
Spark plugs
So you can't connect a MJLJ straight to a pickup, and the synchronised pulse coming out from a MJLJ are highly unlikely to trigger a MSD at the right time
See http://www.bgsoflex.com/mjl/mjl_edis_summary.html for a fairly technical description on how a MJLJ works...
thanks martin
so am i correct in thinking that if i have the 36 tooth wheel,
the ford vr sensor (or maybe the honda pickup??)
then over to the edis module,
then over to the mjlj,
then back to the module ,
then from the module the spark signal would go to the msd ??
then over to the coil in the plug cap coils...
so i assume theres a spark signal from the edis for cyl 1 and 4 and another for cyl 2 and 3 .so i could perhaps just put those signals to my 1 and 2 cyls inputs on the msd ??or maybe the spark signal from thedis works on the neg side of the coils and sends themn to earth at the right time,but hols on a mo ,thats wat points do and they will deff trigger the msd .hmmm .watjafink
??also any data on the max rpm q anybody??
thanks again martin appreciate your help.
the ford vr sensor (or maybe the honda pickup??)
then over to the edis module,
then over to the mjlj,
then back to the module ,
then from the module the spark signal would go to the msd ??
then over to the coil in the plug cap coils...
so i assume theres a spark signal from the edis for cyl 1 and 4 and another for cyl 2 and 3 .so i could perhaps just put those signals to my 1 and 2 cyls inputs on the msd ??or maybe the spark signal from thedis works on the neg side of the coils and sends themn to earth at the right time,but hols on a mo ,thats wat points do and they will deff trigger the msd .hmmm .watjafink
??also any data on the max rpm q anybody??
thanks again martin appreciate your help.
I'm confused....
This is all rather complicated...what are you trying to do?
- use just one sensor?
- get variable ignition timing?
The EDIS module is in the earth side of the coils so switches the coil open circuit/to ground at the appropriate time - just like points do
The bottom line is that MJLJ works great with a 36-1 wheel, a Ford VR sensor, an Ford EDIS module and a Ford wasted spark coil on 4, 6 and 8 cylinder engines (note that the EDIS and coil are diferent for each number of cyliders).
I suspect the coil can be changed for another make easily, but I wouldn't fiddle with anything else - and even if you don't fiddle, it needs competent electronic and computer skills to get it all to work properly.
My knowledge of 2 cylinder bike engines is close to zero - do you spark both cylinders at the same time? If so, I think maybe you have an even more fundamental problem - I can't get my head round whether a 4 cylinder EDIS set up can be used on a twin cylinder bike engine at all
With regard to rpm, common opinion is that MJLJ is good for around 9500 rpm on a 4 cylinder engine - so may not be good enough for you anyway.
Good luck......let us know if it works!
- use just one sensor?
- get variable ignition timing?
The EDIS module is in the earth side of the coils so switches the coil open circuit/to ground at the appropriate time - just like points do
The bottom line is that MJLJ works great with a 36-1 wheel, a Ford VR sensor, an Ford EDIS module and a Ford wasted spark coil on 4, 6 and 8 cylinder engines (note that the EDIS and coil are diferent for each number of cyliders).
I suspect the coil can be changed for another make easily, but I wouldn't fiddle with anything else - and even if you don't fiddle, it needs competent electronic and computer skills to get it all to work properly.
My knowledge of 2 cylinder bike engines is close to zero - do you spark both cylinders at the same time? If so, I think maybe you have an even more fundamental problem - I can't get my head round whether a 4 cylinder EDIS set up can be used on a twin cylinder bike engine at all
With regard to rpm, common opinion is that MJLJ is good for around 9500 rpm on a 4 cylinder engine - so may not be good enough for you anyway.
Good luck......let us know if it works!
what im trying to do !
im trying to get variable timing .as far as i can tell .the mjlj is a system that takes a frequency reading from a toothed wheel.and converts in into a variable delay on the earth side of either 2 or 3 or 4 coils ,depending on the no of cyl.each coil fires on two cyl and one spark is on a exhuast stroke ,and one on a compression stroke.
now imagine the whole system is used as per normal until you get to the point of connecting the edis to the earth side of the coils ,
you then instead connect it to the trigger input of my msd.
the two cyl engine fires 180 deg apart ,and so would replicate a 4 cyl engine wasted spark system .
except with a 4 cyl engine youd have a coil with two ht leads going to 1 and 4 ,and another coil with 2 ht leads going to 2 and 3 ,
so on my engine one would have a coil with one ht lead for no 1 ,then the another coil for no.2 firing 180 degrees apart.so it seems feasable ,the real prob is the rpm limit ,anybody know what the highest itll work to ?say on a simulation ?
thanks again martin ,sorry for being so confusing.lol
robert
now imagine the whole system is used as per normal until you get to the point of connecting the edis to the earth side of the coils ,
you then instead connect it to the trigger input of my msd.
the two cyl engine fires 180 deg apart ,and so would replicate a 4 cyl engine wasted spark system .
except with a 4 cyl engine youd have a coil with two ht leads going to 1 and 4 ,and another coil with 2 ht leads going to 2 and 3 ,
so on my engine one would have a coil with one ht lead for no 1 ,then the another coil for no.2 firing 180 degrees apart.so it seems feasable ,the real prob is the rpm limit ,anybody know what the highest itll work to ?say on a simulation ?
thanks again martin ,sorry for being so confusing.lol
robert