Setup help needed. D-jet to MSII

[107merc]

Changing my inline 6 cyl. direct port injected, D-Jet to MSII. D-jet uses a set of trigger points with 2 contacts in the base of the distributor
to send a signal to the ECU to tell the injectors to open. First pulse is when Cyl. 1 is at 12deg. BTDC on compression stroke and opens
injectors 1, 3, and 5. Second pulse is when cyl. 6 is at 12deg. BTDC and opens injectors 6, 4 and 2. Each pulse lasts for 150 degrees of the disributor rotation, so 2 pulses per 360deg. dist. cycle. How do I program T/S
to duplicate that injector sequence in MSII?? Any questions, comments, assistance greatly appreciated. Sorry if the info is shown somewhere and I missed it.
Sorry, should have added that we have switched to EDIS so distributor is gone.

[DaveEFI]

MS2 has two injector drivers, so will give you your two banks of injectors same as D Jet and others. But you could probably do better grouping them by firing order rather than 135 and 246. If you want to - the original obviously works too.

In software, you can set the injector drivers to fire simultaneously or alternately, and one or more times per cycle. It's all covered in the Manual.

[107merc]

Sorry, I'm not stating my question clearly enough. Is there a way in T/S to synch the first injector pulse with cyl. 1 at TDC between it's exhaust/intake stroke
and the second pulse synched with cyl. 6, TDC. between it's exhaust/intake stroke. Or is the pulse just random?? I'm trying to duplicate the original Benz setup. Thanks.

[DaveEFI]

Since you're firing three injectors at once, there's not much point trying to sync accurately to any one cylinder in that group. You'd normally use at least two squirts per cycle anyway.

If you do want to inject at a particular point in the engine cycle, you'll need MS3X which has 8 injector drivers. You'll also need a cam position sensor. That will then give you sequential - rather than batch - injection.

[dontz125]

MS2 can run 3 injectors for semi-sequential timed injection, no cam signal needed. If you're running EDIS you have a 36-1 crank wheel and sensor, which is all you need for semi-seq.

[107merc]

Thanks everyone for responding. As you can tell I am new at this and really appreciate the assistance.
So I have a basic question, what tells the MSII to ground inj1 then inj 2 leads to fire the injectors??
Where is it's signal coming from or is it just random?? It's also been suggested I get rid of the EDIS
controller and use the MS to drive the coils using the existing 36-1 wheel then I can setup T/S to fire the injectors at a specific crank angle,
as Dontz125 also suggested, but that would mean messing with the inside of the MS. All this help is much appreciated.

[dontz125]

So I have a basic question, what tells the MSII to ground inj1 then inj 2 leads to fire the injectors??
Where is it's signal coming from or is it just random??

The crank position sensor tells the MS processor what the position of the crank is, and how fast it's turning. The processor does a bunch of math, then decides when and for how long it needs to ground the injectors. Something like an EDIS module only tells the processor how fast the engine is turning, but not where it is at any given time. The processor can still do the math for 'how long', but 'when' is just broken down into "once per trigger pulse," which is generally once per cylinder. And you're right; untimed batch injection is pretty random as to where it starts when the engine is first cranked over, but it stays pretty regular after that - every 120 degrees, assuming 6 squirts for two injectors on your inline 6.

It's also been suggested I get rid of the EDIS controller and use the MS to drive the coils using the existing 36-1 wheel

Yes.

then I can setup T/S to fire the injectors at a specific crank angle

Yes.

but that would mean messing with the inside of the MS.

Yes. See? It's easy - you're getting it already!

[107merc]

So I have a basic question, what tells the MSII to ground inj1 then inj 2 leads to fire the injectors??
Where is it's signal coming from or is it just random??

The crank position sensor tells the MS processor what the position of the crank is, and how fast it's turning. The processor does a bunch of math, then decides when and for how long it needs to ground the injectors. Something like an EDIS module only tells the processor how fast the engine is turning, but not where it is at any given time. The processor can still do the math for 'how long', but 'when' is just broken down into "once per trigger pulse," which is generally once per cylinder. And you're right; untimed batch injection is pretty random as to where it starts when the engine is first cranked over, but it stays pretty regular after that - every 120 degrees, assuming 6 squirts for two injectors on your inline 6.

It's also been suggested I get rid of the EDIS controller and use the MS to drive the coils using the existing 36-1 wheel

Yes.

then I can setup T/S to fire the injectors at a specific crank angle

Yes.

but that would mean messing with the inside of the MS.

Yes. See? It's easy - you're getting it already!

Thanks again, the clouds are starting too part. So if I still had a distributor the tach signal from it would tell the MS to fire the injectors??
Would it be at a specific point, ie TDC on #1 cyl?? Am I missing this info in the Manual??

[dontz125]

Most dizzys, whether points (old) or VR (new), only provide a speed signal, so injection is untimed batch. Some dizzys include a 'crank angle sensor', which is some means of telling the MS where the crank is - missing tooth wheel, non-missing-tooth plus single tooth, sheet metal disk with lots of holes, etc. It depends on the make and model of engine, plus if the dizzy is OEM or aftermarket.

There *IS* something called 'sequenced batch injection', that allows some control over where and when batch injection takes place. I haven't done any study of it but it has been discussed, so your best bet is to do some reading in the manual and in the forum.

[107merc]

Thanks again. Going to print this out and put in my "notes" folder.

[DaveEFI]

You can use EDIS and have an cam position sensor to give you the information for sequential. Since you can fit a distributor, the usual way is to modify one to provide that cam sighal. All that is needed is something like a half moon trigger wheel inside it and a sensor. It doesn't need a high resolution trigger wheel, as the timing is provided by the crank trigger. The dizzy only has to tell MS what part of a cycle the engine is on, which the crank trigger can't.

Since you already have EDIS and an MS2, I'd just use that as is. It's not going to be worse in any way than the original setup, and very likely much better. And pretty easy to get working well and tune. I've been running just that on an RV8 for many years. Being a bit of a fiddler, I am intending going MS3X with fully sequential injection one day, though.

[dontz125]

I don't follow much with EDIS, but I'm fairly certain sequential-EDIS is MS3-only. Since the EDIS signal in this case is 6-0 with no missing 'tooth', you would need a single cam tooth vs a half-moon (which is also MS3-only).

EDIS and MS2 means wasted-spark and batch-fire injection. If you rip out the EDIS module, you have a 36-1 crank input that will allow wasted spark and semi-sequential injection.

[DaveEFI]

Ah - right. I really didn't look at what MS2 could do even with substantial modification. As an MS3X seemed to easier way to do what I intend. And that can do sequential injection with a full EDIS igntion set-up. Thing with EDIS is it's so bomb proof I'd want some seriously good reason to change it.

[racingmini_mtl]

Thing with EDIS is it's so bomb proof I'd want some seriously good reason to change it.

Anything that requires spark cut will require you to get rid of the EDIS module.

Jean

[piledriver]

Ah - right. I really didn't look at what MS2 could do even with substantial modification. As an MS3X seemed to easier way to do what I intend. And that can do sequential injection with a full EDIS igntion set-up. Thing with EDIS is it's so bomb proof I'd want some seriously good reason to change it.

There is actually an option to use MS2 with an MS3X... Dontz had a lot to do with it, he laid out the final boards.
It works extremely well, and was designed to almost eliminate the need to modify the ECU, most of the config jumpers are on the adapter board.

If you have NOT bought the ECU yet, and want full sequential using an MS3X with all its lovely I/O, go MS3+MS3X instead, as the MS3 is not really that much more $$$ vs. a MS2 daughterboard, and the MS3 is a lot more capable.

[DaveEFI]

Thing with EDIS is it's so bomb proof I'd want some seriously good reason to change it.

Anything that requires spark cut will require you to get rid of the EDIS module.

Jean

Yes, indeed. However, if EDIS is already fitted and worked OK, no point in changing it. Unless you want to add that feature. With a new installation, and being new to MS, it can make sense to do things in stages. It also depends on the engine whether you need a spark based rev limiter.

[107merc]

I am going to leave the EDIS setup for now as everything is already wired in. My fuel setting will be 6 squirts per cycle and alternating for staging.
Did notice when reading the manual section for "toothed wheel" they specify .75-1mm gap between the sensor and toothed wheel, the EDIS section doesn't
specify anything. Again, thanks and any comments appreciated.

[prof315]

I am going to leave the EDIS setup for now as everything is already wired in. My fuel setting will be 6 squirts per cycle and alternating for staging.
Did notice when reading the manual section for "toothed wheel" they specify .75-1mm gap between the sensor and toothed wheel, the EDIS section doesn't
specify anything. Again, thanks and any comments appreciated.

6 squirts alternating is NOT a good idea. The injector dead times will eat up all of your idle pulse width

[107merc]

I am going to leave the EDIS setup for now as everything is already wired in. My fuel setting will be 6 squirts per cycle and alternating for staging.
Did notice when reading the manual section for "toothed wheel" they specify .75-1mm gap between the sensor and toothed wheel, the EDIS section doesn't
specify anything. Again, thanks and any comments appreciated.

6 squirts alternating is NOT a good idea. The injector dead times will eat up all of your idle pulse width

What would be a good place to start for initial startup?? Any comments appreciated on the gap stated above. I set mine at about 3mm as
nothing was specified in the EDIS section.

[Paul_VR6]

2/alternating and don't give it much more thought.