Dodge truck V10 support

[E4ODnut]

Well, this doesn't seem to be working, perhaps I should re-phrase the question.

The on line help states, in several places, that if you are not sure of a setting, ask for help on the forum.

I'm not sure of some settings, so I am asking for help.

I don't want to break anything because I have not understood the set up correctly. It is in no ones best interest to do that. I realize that the engine I am working with is an orphan, and there are probably few if any people, other than the developers on this forum with any practical experience with it. I have a pretty good understanding of how the engine works, but I'm not confident that I know how MS3 works when configured for the Viper Gen 1, waste spark, semi-sequential injection.. I need to know this in order to make sure I have my settings and wiring connections correct in order for MS3 to do what I want it to do.

Let's start with the waste spark ignition. It is my understanding that when MS3 establishes synch, it will fire Spark A at the appropriate time. 54 crank degrees later it will fire Spark B. 90 degrees later it will fire Spark C. 54 degrees later it will fire Spark D. 90 degrees later it will fire Spark E. 54 degrees later it will fire Spark A again. 90 degrees later it will fire Spark B again, 54 degrees later it will fire Spark C again. 90 degrees later it will fire Spark D again. 54 degrees later it will fire Spark E again. 90 degrees later it will fire Spark A again. This completes two engine revolutions (one 720 degree engine cycle) and the sequence is the repeated. When I check with the I/O pins list showing usage it shows Spark A,B,C,D and E as spark outputs.

Is this correct?

Let’s try fuel now. This I am not clear on at all. I had assumed that it would work in a similar fashion to waste spark. After MS3 establishes synch and following the delay settings in the injector timing table, it will fire Injector A. 54 crank degrees later it will fire Injector B. 90 degrees later it will fire Injector C. 54 degrees later it will fire Injector D. 90 degrees later it will fire Injector E. 54 degrees later it will fire Injector A again. 90 degrees later it will fire Injector B again, 54 degrees later it will fire Injector C again. 90 degrees later it will fire Injector D again. 54 degrees later it will fire Injector E again. 90 degrees later it will fire Injector A again. This completes two engine revolutions (one 720 degree engine cycle) and the sequence is the repeated. But, when I check with the I/O pins list showing usage it shows Injector A,B,C,D,E,F,G,H,Inj Bank1 and Inj Bank2 as primary injectors. I should only need 5 injector channels, and yet, the list indicates that I am using 10.

James stated that the injector channels are fired in pairs. How are they paired and in what order do they fire?

Let’s try sequential injection now. Are the injector channels A through J fired in order, in the 54 degree 90 degree sequence for the 720 degree engine cycle, and then repeated?

I can’t really do much more until I have this cleared up.

[CRSTune]

You are correct. The ignition outputs and fuel outputs fire in order, A, B, C, D, etc.

For fuel being fired in pairs, they'll fire A-E but F-J will also fire, whether something is connected to them or not in semi-sequential mode. In other words, A&F, then B&G, etc. If you switched the software to full sequential injection, it would fire the injectors A-J, in that order.

The ignition outputs do the same thing. The difference is that you're able to specifically select waste spark in the settings so the ECU will only fire outputs A-E. Now, if you had selected waste spark COP, it would fire A-E AND F-J, paired just like the injectors (assuming you had 10 ignition outputs that is).

[E4ODnut]

Excellent! Thanks so much for your prompt response.

Now, it looks like I am going to have to get a bit creative in order to have the injector channels firing in the OEM order. The injectors are connected together in the loom. 1&10, 9&4, 3&6, 5&8, 7&2. They are fired in the 54/90 degree sequence of 1&10, 1&10, 9&4, 9&4, 3&6, 3&6, 5&8, 5&8, 7&2, 7&2, repeat. It doesn't look like I can use the "semi-sequential" injection mode, but I think I can use "sequential".

I think I can set injection to "sequential" and do this:
Connect Inj A and Inj B together and connect them to 1&10
Connect Inj C and Inj D together and connect them t 9&4
Connect Inj E and Inj F together and connect them to 3&6
Connect Inj G and Inj H together and connect them to 5&8
Connect Inj I and Inj J together and connect them to 7&2

Any flaws in my logic?

[CRSTune]

Yes. The main flaw is the way injector on time is calculated. The ECU calculates the required PW based on the dead time, req fuel, VE table, and correction factors. Then the time to begin the injection is calculated based upon the injection timing settings, whether they be start, middle, or end of injection. This is important with respect to the valve opening/closing events. If you pair outputs A and B together for example, these times may overlap or interfere. Injector A's PW will either end too late or injector B's PW will begin too soon. This will make for inconsistent fueling between the cylinders, not to mention that the ECU is no longer calculating an accurate PW.

[E4ODnut]

Hmm. I thought I understood how the factory managed the fuel, based on the way the injectors were wired and the position of the notches in the crank trigger wheel with respect to the intake valve opening time. I could be wrong, it wouldn't be the first time. This requires some more pondering.
Thanks very much for your help.

[CRSTune]

To me, it looks like the factory wanted the fuel to be controlled like it was a 5 cylinder engine (90+54=144, same as an even fire 5 cylinder). Thus, the ECU would've been programmed for that kind of control, likely using start of injection timing, firing once onto a pair of injectors, and a limit to the PW to ensure they fired only on a closed valve. That's my guess.

[E4ODnut]

I think I've figured it out, wired as follows:

Injector A to Injectors 1&10
Injector B to Injectors 5&8
Injector C to Injectors 9&4
Injector D to Injectors 7&2
Injector E to Injectors 3&6

I'll post details on my logic later this evening to see if you can poke holes in it.

[E4ODnut]

OK. Here’s the logic.

The valve timing is:
Exh Open 60 BBDC
Exh Close 25ATDC
Int Open 6 BTDC
Int Close 61 ABDC

The injectors are paired in the firing order. 1&10, 9&4, 3&6, 5&8, 7&2. The second cylinder in a pair will have its valve timing 54 degrees after the preceding cylinder in that pair. The notches in the crank trigger wheel align with the injection points.

Injector channel A is connected to injectors 1&10 and fires at 6 degrees BTDC between exhaust and Intake. The intake valve on #1 is just starting to open, the intake valve on #10 is 54 degrees before opening. The crank rotates 54 degrees and fires Injector B.

Injector channel B is connected to injectors 5&8 and fires at 6 degrees BTDC between exhaust and Intake. The intake valves on both cylinders are closed. The crank rotates 90 degrees and fires Injector C.

Injector channel C is connected to injectors 9&4 and fires at 6 degrees BTDC between exhaust and Intake. The intake valve on #9 is just starting to open, the intake valve on #4 is 54 degrees before opening. The crank rotates 54 degrees and fires Injector D.

Injector channel D is connected to injectors 7&2 and fires at 6 degrees BTDC between exhaust and Intake. The intake valves on both cylinders are closed. The crank rotates 90 degrees and fires Injector E.

Injector channel E is connected to injectors 3&6 and fires at 6 degrees BTDC between exhaust and Intake. The intake valve on #3 is just starting to open, the intake valve on #6 is 54 degrees before opening. The crank rotates 54 degrees and fires Injector A again.

Injector channel A is connected to injectors 1&10 and fires at 6 degrees BTDC between exhaust and Intake. The intake valves on both cylinders are closed. The crank rotates 90 degrees and fires Injector B again.

Injector channel B is connected to injectors 5&8 and fires at 6 degrees BTDC between exhaust and Intake. The intake valve on #5 is just starting to open, the intake valve on #8 is 54 degrees before opening. The crank rotates 54 degrees and fires Injector C again.

Injector channel C is connected to injectors 9&4 and fires at 6 degrees BTDC between exhaust and Intake. The intake valves on both cylinders are closed. The crank rotates 90 degrees and fires Injector D again.

Injector channel D is connected to injectors 7&2 and fires at 6 degrees BTDC between exhaust and Intake. The intake valve on #7 is just starting to open, the intake valve on #2 is 54 degrees before opening. The crank rotates 54 degrees and fires Injector E again.

Injector channel E is connected to injectors 3&6 and fires at 6 degrees BTDC between exhaust and Intake. The intake valves on both cylinders are closed. The crank rotates 90 degrees and fires Injector A again.

This completes the 720 degree engine cycle. The fuel has been injected for each cylinder, half on a closed intake valve, and half on an open intake valve, almost. The leading cylinder in a pair has the injection point at the start of the opening of the intake valve, but the trailing cylinder in the pair has the injection point 54 degrees before the intake valve starts to open. This is not an ideal situation because fuel distribution won’t be quite as good as with true sequential injection, but it is still a lot better than batch injection would be. The V10s are noted for their smooth idle at 14.7 AFR so the factory must have done something right in that regard.

Anyway, that is how I have it figured now, in retrospect; it makes a lot more sense than what I previously thought. What do you think?

[CRSTune]

How about this much simpler solution.

Configure your outputs as such:
A: 1/10
C: 9/4
E: 3/6
G: 5/8
I: 7/2
Leave the unused outputs disconnected.

Configure your settings for full sequential injection, 1 squirt/simultaneous. Select "end of injection timing" and populate your entire table to end injection at a minimum of 366deg. This gives you a maximum 58% duty cycle in which fuel will always hit a closed valve, which is plenty. This matters more for low load/rpm.

You've now likely replicated the original factory implementation. The injectors will only fire once (unless you configure more squirts) and will likely always fire on a closed valve. There may be small atomization differences between the cylinders due to the 54deg of difference (the second cylinder will heat the fuel longer than the first) but I wouldn't be too worried.

[E4ODnut]

Yes, that does look like another option. I think what I will do is to make provision in the wiring to be able to easily change the physical connections to the injector outputs to be able to experiment, but I'd like to try it the way the factory does first, which bring me to my next question.

I can't find any reference anywhere in any of the manuals as to what the "squirts per engine cycle" and "injector staging" should be for semi sequential. I had expected there to be an option for 10 squirts alternating, but I don't see that. Because I want to fire the injectors twice per cycle I would expect the Req Fuel value in the small box, which I believe is the one used for the PW calculations, to be half of the calculated Req Fuel value on the large box. The only way I can get this is to select select "2 squirts simultaneous". Would that be the correct setting for semi sequential?

I'll probably experiment with the injection angle and it's specification when I am tuning, but I'd like to start by setting my injection timing to begin at 6 degrees BTDC between the exhaust and intake stroke. This should result in one squirt falling on a closed intake valve, and one falling on an opening intake valve, (except that the trailing cylinder will start on a closed valve). In order to get the 6 degree BTDC angle, should settings in the Injection Timing Table be 366 degrees or 354 degrees?

Oh, one more thing. I'm curious as to how you were able to calculate the 58% duty cycle?

[jsmcortina]

In MS3, the "num squirts" setting is a hangover from the batch fire mode. Set it to 1 squirt simultaneous.

For a regular port injected engine, the injection angle isn't going to prevent you from starting the engine. Proceed to that step and then experiment for the best injection angles.

James

[E4ODnut]

1 squirt simultaneous results in both Req fuel values being the same. Is this correct?

There appears to be an error in the MS3 set up manual, section 4.1, page 80 states that for cylinders above 8, semi-sequential operates a single output per injector pair.

[CRSTune]

I'll probably experiment with the injection angle and it's specification when I am tuning, but I'd like to start by setting my injection timing to begin at 6 degrees BTDC between the exhaust and intake stroke. This should result in one squirt falling on a closed intake valve, and one falling on an opening intake valve, (except that the trailing cylinder will start on a closed valve). In order to get the 6 degree BTDC angle, should settings in the Injection Timing Table be 366 degrees or 354 degrees?

You would set it to 366deg.

[E4ODnut]

I just had another look at 4.1.3 page 81 of the MS3 set up manual. Looks to me like either 366 or -354 should do the same thing.
Thanks.

[E4ODnut]

Tachometer setting.
The stock ECU has an interesting tachometer output. The factory service manual states that at 3000 RPM it should have a frequency of 125 Hz. I confirmed this with my personal scope. Nice square wave at ~5 volts. If I'm reading the tachometer settings right I should have them set to :
On
Tacho
Variable
250

Is this correct?

[E4ODnut]

The MS3 Tacho output is a 12 volt square wave. The stock tachometer expects a 5 volt square wave. Can the output voltage be changed from 12 to 5 V internally?

[Matt Cramer]

Use a different output pin and put a 5 volt pull up on it.

[E4ODnut]

Do I do that from the Tacho Output section under Basic/Load Settings, or any of the Generic PWM Outputs under Advanced Engine?

[CRSTune]

Do I do that from the Tacho Output section under Basic/Load Settings, or any of the Generic PWM Outputs under Advanced Engine?

Tacho Output

[E4ODnut]

Thanks.
I have another problem. I want to create a PWM output with a variable frequency, but the highest % number TS will allow me to enter is 250. How do I increase this?