Magnum ignitions on MS-II Step 4: Having it fire the spark

[Matt Cramer]

Here's the point where you get the Megasquirt firing the coil.

Install a VB921 or equivalent IGBT in the Q16 slot if you do not already have one.

Solder a 330 ohm resistor to a length of wire and cover the resistor with heat shrink tubing.

Run this resistor-on-a-wire combination from the top of R26 to IGBTIN.

Jumper IGBTOUT to IGN.

The next step will be only for those who want to remove the stock PCM and do not need control over certain items the Megasquirt does not handle like the transmission control.
This completes the hardware mods. Wire pin 36 to the negative terminal of the ignition coil after you have entered in the MegaTune settings below.

MegaTune settings:

Under Ignition Options, make the following settings.

Spark mode: Toothed Wheel
Trigger Offset: 0
Ignition Input Capture: Falling Edge
Spark Output: Going High (Inverted)
Number of Coils: Single Coil
Spark A output pin: D14

Set the dwell type to standard dwell, and start with a low setting like 1.5 msec. Too much dwell can damage a VB921. Take the case off when adjusting dwell and check the temperature of the VB921 with your finger. If it feels like it has a fever, shut the ignition off at once.

Trigger wheels settings

Trigger wheel arrangement: Dual Wheel
Trigger Wheel Teeth: 8
Tooth #1 Angle: This was found in step 3. If you skipped step 3, try 20 and adjust as needed.
Wheel speed: Crank wheel
Second trigger active on: Rising and Falling
and every rotation of: Crank

You'll need to adjust the Tooth #1 Angle number to get the spark timing in MegaTune to match the spark timing you find with the timing light.

[4x4 98]

Thaks for this step,

Because I have changed the input for the cam pos sensor I must rewire it for the trigger output?

I have already Jumpered IGBTOUT to IGN, and I have already a VB921 in.

I must check these wit the stock PCM connected and hope it will work because of the problem in stepII.


Thanks and greetings,


Erik.

[Matt Cramer]

What firmware version are you using?

[4x4 98]

Hello Matt,

I am using ms extra beta 21

I used pen3 for the extra input for the cam, I removed to remove the wire for the VB921, as MS2/Extra code uses this as an input for the second trigger instead?

Thanks and greetings,

Erik.

[Matt Cramer]

You must use JS10 as the second trigger input so this removes the original ignition output. Use the ignition output in this write-up.

[4x4 98]

I have already changed the JS 10 wire,

Do I need the resistor in the original DIY MSII?


I have already changed IGBTOUT to IGN.

Thanks and greetings,


Erik.

[Matt Cramer]

What resistor is this? I'm not sure I follow the question.

[4x4 98]

Here's the point where you get the Megasquirt firing the coil.

Install a VB921 or equivalent IGBT in the Q16 slot if you do not already have one.

Solder a 330 ohm resistor to a length of wire and cover the resistor with heat shrink tubing.

Run this resistor-on-a-wire combination from the top of R26 to IGBTIN.

.


I meant this resistor, I have the DIYautotune MS-230C I don,t have a degree wheel so I will try 20 for the right angle.

How do check if this oke?



Thanks and greetings,

Erik


Erik.

[Matt Cramer]

This resistor is not included in the kit. You will have to check the timing with a timing light.

[4x4 98]

I will buy a resistor and install it and try.

I will only take the negative coil lead form the stock ECU because I need the other functions from that ECU.

I will try to chechk the timing, I do not know if there is a timing mark on the balancer.

I will let you know ASAP.

Thanks and greetings,


Erik.

[4x4 98]

Hello Matt,

I tried it today and it doesn't work.

When I cranck there is still the light on the dash from check chages, and there is no signal on the rpm clock.

I have tried from 20 degrees to zero, there is no difference at all.

I think it has got something to do with the sharing sensor or something like that.

Like I said before if the MS is not connected the truck will run, (with the coil connected to the stock ecu)

If the MS is connected with the wiring the truck will not run( with or without the coil connected).

The led next to the DB37 is flashing and the second led is burning,the third led is out.

So I geuss It wont work?

Here is a picture from the log :

http://img.photobucket.com/albums/v140/activate1/cranking.png

[Matt Cramer]

Ok, so you're getting RPM. If you check for spark, what do you find? What happens if you try a timing light?

[4x4 98]

I have the dwell tryed to 3.0 ms and still no spark!

I dont have a timinglight now I will try to get one tommorrow.

Thanks and greetings,


Erik.

[4x4 98]

I have checked it today with a timinglight, there is no spark at all.

I have made a wire directly from the battery to the coil, and let the MS on the negative coil but no spark at all.

maybe there is a problem with the VB921 in the MS?

How do I check this?

[Matt Cramer]

VB921s are easily burnt if you turn up the dwell too high. Check it for signs of heat damage - a melted center screw, discolored legs, etc.

[4x4 98]

Hello Matt.

I have none of the things you said I really do not know what the problem is.

Because I am living in Europe, it is not easy for me to get some help....


Greetings,


Erik.

[Matt Cramer]

Ok, what tools do you have to troubleshoot this? Do you have any of the following:

Megasquirt Stimulator
Oscilloscope
Digital multimeter with frequency measuring

Let me know which of these you have access to, and we'll take it from there.

[4x4 98]

I have checked everything again with the MS form the truck and everything is working fine, there is a spark with the Megastim and I can follow the signal with a scope.

If I connected the MS on the wiring in the truck there is no 12V on the coil anymore, the same reason there is a warning on the dash for check cages??

I will try today to connect 12V directly to the coil from the battery and let te MS connected to the minus of the coil.

Normally it must be working then?

It is not that easy to work with......(Dodge):bump:

[Matt Cramer]

Ok, looks like you'll need to change what's connected to the coil + terminal. Instead of wiring it straight to the battery, I'd recommend wiring it to the Megasquirt's main power relay. Start with a low dwell setting. That's likely to get it fixed.

[4x4 98]

Still having the same problems, the ignition led next to the connector is flashing when I am crancking, so That is right.

In the middle of the VB921 there 12 V battery from the coil, on the third leg of the VB921 I have 0 Ohm.

On several stops of the crancking the LED stays on!!!!!(random)

That is a giant mistake, so it looks like it is a software fault?!?!?!?!?!?

I think it is not working with the 8 tooth on the crank and the 180 degree sensor tooth on the camshaft?

My coil and the vb921 already died..........


Is there something I can change on the software to make it work?

Greetings,


Erik

on sec

[Matt Cramer]

Post a copy of your MSQ file and I can check if there's any setting problems in it.

[4x4 98]

I send a copy to your emailadress because it is to lonh to post it here.

I can not find anything wrong in it, maybe I am wrong

Thanks and greetings,


Erik

[4x4 98]

Hello Matt,

Did you find something in the MSQ file?

Greetings,


Erik.

[mtlcafan79]

Have you posted on any of the megasquirt forums yet?

[4x4 98]

I have not posted it yet, two other guys in Europe look at it but could not find anything wrong with it?

[Matt Cramer]

I see you're still running beta code instead of the latest release. I would first recommend upgrading to the release code 2.0.1.

[4x4 98]

Hello Matt,

Thanks for the answer, I already have done that a week ago, still the same problem!

With the megastim everything is working fine, on the Dodge it is not working!

It seems the problem is in the dodge camshaft sensor, I will try to use a 36-1 triggerwheel to let it work!

[Matt Cramer]

We've seen a similar camshaft sensor work on other applications, but some of the settings and mods still need to be determined. The 36-1 wheel is a known combination, but I still suspect it's possible to get it working with the factory sensors.

[4x4 98]

Hello Matt,

Maybe it is possible but there is defently something wrong with my setup and I do not know what.

I have used the other inputs with no problem : clt tps iat but there is a problem with firing the coil.

I already burnt my VB921 and a coil, while it worked fine on the Megastim.

If you know a solution, I hope I hear it!


Thanks and greetings,


Erik.

[Matt Cramer]

Would you be willing to run a couple of voltmeter tests on this to see if we could find where the problem is? To do these, you'd need to disconnect the injectors and coil, and crank the engine (or have someone turn it slowly with a breaker bar) with the Megasquirt case open. Check with a volt meter on pin 14 of the daughter card for the crank signal and the JS10 jumper for the cam signal. Both of these should give signals that bounce from 0 to 5 volts and back. The crank signal should give 16 pulses for every one pulse of the cam signal. What do you find, in terms of voltage and the number of pulses?

[4x4 98]

IHello Matt,

I haven't much time to test, but if I remove the wires from the Cam and cranck the engine will run with the MS connected!!!

Then the dash still works and no check cages?!?!?

[Matt Cramer]

Ok, so the MS is triggering off the crank sensor and controlling fuel only - is that correct? Could you post the MSQ that it's using for this?

[4x4 98]

Hello Matt,

I hust removed the two wires from the CPS and the CPS that is the only thing I did.

The engine is running now with al the other sensors connected ans they are showing the right data.

[Matt Cramer]

By CPS, do you mean the camshaft position sensor or the crankshaft position sensor?

I take it the Megasquirt is still wired to the crankshaft position sensor?

[4x4 98]

Hello Matt,

I have only removed the wire for the CAM sensor, the MS is still wired to al the other sensors....

The only thing I still need is another VB921 or the Bosch type instead because the original is toasted.....

Maybe I need four off them to make it to a DIS system...

Can you make a good price inclusing shipping by PM??

Thanks and greetings,

Erik.

[Five9Dak]

Whats the status on this project?

Matt, I read on http://www.msextra.com/viewtopic.php?f=101&t=29172 about a user with getting a magnum engine running with the stock crank and cam sensors. Have you personally got one working yet? I am about to install an MSII v3.0 on my truck within the next month and if you are willing to help me out maybe we get a solid set of instructions/hardware modifications to make the magnums more plug and play with MSII.

[Matt Cramer]

Whats the status on this project?

Matt, I read on http://www.msextra.com/viewtopic.php?f=101&t=29172 about a user with getting a magnum engine running with the stock crank and cam sensors. Have you personally got one working yet? I am about to install an MSII v3.0 on my truck within the next month and if you are willing to help me out maybe we get a solid set of instructions/hardware modifications to make the magnums more plug and play with MSII.

Yes, I've seen that thread too and I plan to develop it into a tech article. I'll post the first draft on this site soon and, if others report that it works well, we'll turn it into a complete tech article.

Unfortunately, we don't have a Magnum powered truck hanging around the shop. While we have two Dodges, one is a '66 Dart with a turbo slant six, and the other is a four banger Ram 50.

[Five9Dak]

Unfortunately GA is quite a trip from PSU. As soon as you get any sort of instruction I'm willing to try it out.

I don't remember this ever being addressed, can the MS and PCM share the crank and cam? (I would think this is required for transmission control)

[Matt Cramer]

I don't remember this ever being addressed, can the MS and PCM share the crank and cam? (I would think this is required for transmission control)

It's likely they can, although it will take a bit of testing to find out if the circuits in the MS need to be tweaked. I believe the guy who had it running had the stock PCM removed.

[4x4 98]

Hello,

I have tried with the stock ECU in and it won't work..

I cost me a coil and VB.

[Matt Cramer]

The guy on MSExtra had come up with a new version of the mods. Whether they will work with the stock ECU or not will take some testing. I'm pretty sure the burned coil and VB921 did not have anything to do with leaving the stock ECU in place unless you'd also attempted to wire the stock ECU to the coil at the same time.

[4x4 98]

hello Mat,
I Did not wire it at the same time, it had something to do with the signals of the cam or crank.

Thanks and greetings,


Erik.

[Matt Cramer]

Burning the VB921 and coil is an output problem, and has nothing to do with the input side of things. My guess is you may have accidentally set too much dwell as I've seen that kill both of them before.