MSefi.com read only forum (Jan.15,2018)

New and after reading for days I need clarification on triggering the MS2.
I'm going to be using a MS2 Ver 3.0 board with a crane or msd box and a msd Ready to Run Distributor.
I've read to connect the orange wire from the ready to run distributor to the tach in signal pin 24 and then use the tach out pin 36 connected to the white wire points input wire on the msd box.
I read to configure the MS2 for a point setup but one set of instructions say to use the hall setup and the other says to use the VR setup. The VR setup says that is the latest info with the newer boards.
Apparently I should also use a pullup resistor.
My first question is should I use the VR setup or the hall setup to trigger the MSD Ready to Run Distributor?
My second question is why do I need the input pullup when the ready to run distributor should be providing 12 volts out and ground when it's triggered? Maybe it doesn't matter if it's added anyway?
Thirdly I've read that the Ready to Run MSD Distributor will output multiple coil firing pulses at low rpm and wonder how the MS2 deals with this? It must see it as noise and disregard it or will it cause a faulty tach input signal?

Thanks for the help.
Keith

The distributor should theoretically work with either input circuit. A pull up resistor would not be needed if it puts out a 12 volt to ground square wave. However, I suspect the signal it puts out is a floating to ground signal - in which case you will need a pull up resistor to make that 12 volts instead of floating.

Matt Cramer wrote:The distributor should theoretically work with either input circuit. A pull up resistor would not be needed if it puts out a 12 volt to ground square wave. However, I suspect the signal it puts out is a floating to ground signal - in which case you will need a pull up resistor to make that 12 volts instead of floating.

Thanks Matt,
Would there be any advantage to setting the MS2 for VR over the Hall with this distributor?

I'm not sure there is a major difference either way.

Ok Thanks Matt.

Just wondering if anyone else on here has some experience with a MSD Ready to Run distributor and a MS2?

Thanks,

Keith

kman521 wrote:

Matt Cramer wrote:The distributor should theoretically work with either input circuit. A pull up resistor would not be needed if it puts out a 12 volt to ground square wave. However, I suspect the signal it puts out is a floating to ground signal - in which case you will need a pull up resistor to make that 12 volts instead of floating.

Thanks Matt,
Would there be any advantage to setting the MS2 for VR over the Hall with this distributor?

I'd guess you've also been reading the Extra manual. They seem to have standardised on the VR input for all primary (crank position) tach inputs, and the opto for the secondary (cam position) since sequential is now more common. To simplify things. The only exception would be fuel only where you get the tach signal from the coil.

With my Hall Effect sensor which gives a square wave output, I found I had to adjust R56 in the VR circuit to get a reliable trigger at all RPM. It's set at at about 8 turns clockwise from the start position.

Thanks Trakkies
Yeah, I've been reading as much as I can trying to sort through the various options for points. It gets a little confusing when one site says to setup for Hall and another says VR.
Then one site says to use a pullup resistor to 5 volts when the other says 12 volts.
I'm actually thinking of modify the stock Mopar VR distributor for locked timing so I can remove the MSD ready to run distributor and just sell it.
I'm not sure there is any advantage to the MSD ready to run with the MS2.

You need to decide if you're going to use B&G or Extra code - then stick to only those instructions. You will get very confused if you read both manuals, since they can do the same sort of things in different ways.

Personally I'd ditch the dizzy totally and go for wasted spark. That would probably mean EDIS if you wish to use B&G code.

It can be tricky to get the rotor arm phasing correct when using a fixed dizzy with the timing mapped by MS. And the tach signal is never going to be as accurate from a dizzy as from a crank sensor.

To sum it up - I'd stick with the standard ignition and use MS fuel only, or if wanting mapped ignition dispense with the dizzy and go wasted spark. Or even sequential with crank and cam sensor - but that will mean Extra Code.

trakkies wrote:You need to decide if you're going to use B&G or Extra code - then stick to only those instructions. You will get very confused if you read both manuals, since they can do the same sort of things in different ways.

Personally I'd ditch the dizzy totally and go for wasted spark. That would probably mean EDIS if you wish to use B&G code.

It can be tricky to get the rotor arm phasing correct when using a fixed dizzy with the timing mapped by MS. And the tach signal is never going to be as accurate from a dizzy as from a crank sensor.

To sum it up - I'd stick with the standard ignition and use MS fuel only, or if wanting mapped ignition dispense with the dizzy and go wasted spark. Or even sequential with crank and cam sensor - but that will mean Extra Code.

I really want to use the MS for ignition timing too.
This is going on a Mopar 440 ci engine using an aftermarket throttle body with four 80 pound injectors under that so sequential is not going to happen.
I'll stick to one setup,
Thanks

Then I'd really consider going wasted spark and no dizzy.

trakkies wrote:Then I'd really consider going wasted spark and no dizzy.

Correct me if I'm wrong but a wasted spark system on a V8 would require a crank trigger and the addition of at least 4 coil packs (maybe 8 ) and wiring.
It seems to me that adding these components to the equation the price of a ms system starts to become less desirable.
Right now I have a crane box and ready to run distributor which I believe I would have to eliminate with the wasted spark setup.

Is it not possible for the MS2 to run reliably up to 6500 rpm on a V8 engine with the normal VR triggering or a Ready to Run MSD distributor and Crane or MSD ignition box?

I experimented with a locked dizzy using its internal VR trigger with MS. On a V8 with peak revs of just over 6000 rpm. Was never 100% happy with it so changed to wasted spark. You may well have more success, though. The main problem I had was with cross firing - having to adjust the sync of the rotor arm to cope with the advance curve I was using.

I think as long as the distributor is fixed and the rotor is phased right it should never change by adjusting the timing in the MS.
Twisting the distributor could affect the rotor phazing and so could where it was originally locked.
I'm going to give it a try with the current equipment I have and if there are problems I've got options.
Right now this is Canadian winter research because of the cold weather. Spring time I'll get to test it all.
Thanks for all your help,
Keith

That's the problem. With mechanical advance the rotor arm also moves relative to the dizzy drive shaft to track the advance curve. When you lock it, the rotor arm has to be positioned (phased) so it covers perhaps 30-50 (crankshaft) degrees of change. It is only actually designed to cope with perhaps 10 degrees of vacuum control.
But it may well depend on the make of dizzy you use if it is a problem in practice. Good luck with yours.

trakkies wrote:That's the problem. With mechanical advance the rotor arm also moves relative to the dizzy drive shaft to track the advance curve. When you lock it, the rotor arm has to be positioned (phased) so it covers perhaps 30-50 (crankshaft) degrees of change. It is only actually designed to cope with perhaps 10 degrees of vacuum control.
But it may well depend on the make of dizzy you use if it is a problem in practice. Good luck with yours.

I'm not really following you.
I've used a locked distributor with an MSD AL6 ignition box and had the timing locked at 36 total with no issues.

With the MS if I lock the distributor for example at 10 degrees and the rotor is sitting centered directly under the proper distributor cap terminal that relationship will never change unless I twist the distributor again and I wouldn't need to.
If I then set the MS software to indicate I am at 10 degrees to match the physical timing and use the timing tables in the ms to change the timing after that the rotor will still be in the same relationship to the distributor cap terminal no matter what the commanded timing is. Rotor phasing won't change and shouldn't be an issue.
The distributor vacuum advance will also be locked out and not in the picture.

OK. Good luck.

Thanks,

Cheers

Here is a link to another site which may be of some help:

http://www.dodgecharger.com/forum/index ... 432.0.html

Aussiemadonmopars wrote:Here is a link to another site which may be of some help:

http://www.dodgecharger.com/forum/index ... 432.0.html

That's an awesome EFI setup but a little too rich for me and I don't have a lathe to fab the custom stuff.

Thanks,
Keith