Need help with project v12

[V12r]

Hey fellas. Longtime reader first time writer;)

I have a quick, I hope, question for y'all. I've d*** near scratched my head bloody.

I am mega-squirting a Mercedes V12 and I've ran into the following issue;

I have 12 injectors wired up for sequential injection. They all fire correctly during the inj-test.
I have 12 LS2 coils that I have wired to fire in pairs. Spark out 1 - coil 1 + 6, Spark out 2 - coil 7 + 12 etc... I cannot get them to fire correctly in test mode. I have tried wasted cop, cop and wasted spark. At most I can get all the left hand, from front, to fire in pairs as they should + cylinder 12. I get the same result when I try cranking.

Do you have any idea of what is going on and what I am going wrong?

I cannot find an option to set number of spark outputs, i.e for me that would be 6 since I have 6 pairs of coils.

Basic info:

MS3-PRO
Firing order: 1-12-5-8-3-10-6-7-2-11-4-9
TDC 355* on the harmonic balancer.
60-2 + VR sensor. Single Toothed CAM + VR sensor
Tunerstudio MS
Mercedes 6.0L V12, M120

Let me know if you need any more info and/or details.

[elutionsdesign]

It will be wasted COP, then it will fire Spark A, B, C, D, E, F. How are the coils wired now?

[V12r]

Spark out. - Coil#
A - 1&6
B - 7&12
C - 5&2
D - 8&11
E - 3&4
F - 10&9

[ekam99]

Spark out. - Coil#
A - 1&6
B - 7&12
C - 5&2
D - 8&11
E - 3&4
F - 10&9

and Wasted spark settings, not Wasted COP

[elutionsdesign]

Yes, wasted spark, my bad and thanks for the correction. V12r, what I meant was physically how have you wired up the coils, power, grounds, trigger wire? Can you post a diagram?

[V12r]

Yes, wasted spark, my bad and thanks for the correction. V12r, what I meant was physically how have you wired up the coils, power, grounds, trigger wire? Can you post a diagram?

LS2 Coil

A+B - Ground
C - Signal from MS3
D - 12V

[Laminar]

Awesome project, I think Megasquirt can really save these V12s with their ridiculously complicated and expensive electronics. What are you doing for throttle bodies?

[V12r]

Awesome project, I think Megasquirt can really save these V12s with their ridiculously complicated and expensive electronics. What are you doing for throttle bodies?

I am using a couple of 95 mustang 70mm throttle bodies.

[elutionsdesign]

Going high or low and what test dwell?

[jsmcortina]

[Tinkers Toy]

I have an 1994 SL600 with this same engine running on nearly the same setup except I run semi sequential fuel and wasted spark since I do not have a cam signal. I run a 36-1 wheel mounted on front of my harmonic balancer and some homemade brackets for the sensor to get a crank signal .

Where are you getting your cam signal from? The stock cam sensors are triggered by two magnets on the cam 120 degrees apart, did you remove one of the magnets? I am interested in going sequential if I can easily get a cam signal. I don't have access to the front of the cams because of where I had to mount two of the coils.

Where did you mount all the coils? I attached a picture, mine are mounted between the intake runners except for coil1 and coil 12 which are mounted on brackets behind the distributor covers.

1994 Mercedes on Mega Squirt LS2 coils, V12, lots of wires.jpg

[Tinkers Toy]

I'll attach my Tuner Studio settings but again I'm semi fuel and wasted spark. I also wired 2 coils together the same as you have. My injectors are wired together where yours are individually wired.36-1 toothed wheel. I used GM throttle bodies with integral TPS and stepper IAC.

TunerStudio settings.png

[Tinkers Toy]

one last comment. Do you have both coils wired to the same trigger wire from MS? Older documentation in the manuals said you could wire the coils separately when using wasted spark to make conversion to sequential spark easy. This is not true. You need to attach both coils to the same wire.

If you had the coil triggers wired together you would have to have spark at coil 7 if you had spark at 12. If coil 7 and 12 are wired together, unless you have a bad coil, 12 and 7 have to both be working.

I think I recall having similar issues until we realized the documentation needed correcting and the wasted spark had to be done by physically wiring both coil sets together not only by settings in MS.

[Tinkers Toy]

sorry for all the replies, I just reread your post. You will still set the number of cylinders to 12 in the Engine and Sequential Settings area. When you select wasted spark, MS will turn off spark outputs G through L. since spark output D is physically wired to both 7 & 12 both cylinders should spark at the same time.

If you are using LS2 D585 coils with the built in heat sinks you could copy my dwell settings.

[V12r]

I have wired each spark output to two coils, I do not have the coils with the heatsink on it.

I am attaching my MSQ that I forgot last time.


I did remove one of the magnetic pickups on the cam. I made a bracket that bolts onto the fuel rail that holds all the coils.

[V12r]

I have an 1994 SL600 with this same engine running on nearly the same setup except I run semi sequential fuel and wasted spark since I do not have a cam signal. I run a 36-1 wheel mounted on front of my harmonic balancer and some homemade brackets for the sensor to get a crank signal .

Where are you getting your cam signal from? The stock cam sensors are triggered by two magnets on the cam 120 degrees apart, did you remove one of the magnets? I am interested in going sequential if I can easily get a cam signal. I don't have access to the front of the cams because of where I had to mount two of the coils.

Where did you mount all the coils? I attached a picture, mine are mounted between the intake runners except for coil1 and coil 12 which are mounted on brackets behind the distributor covers.

1994 Mercedes on Mega Squirt LS2 coils, V12, lots of wires.jpg

How did you mount the coils?

[Tinkers Toy]

I removed the mounting tabs on 10 of the coils and wedged them in the spot between the intake runners, the round LS2 D585 coils fit perfect. I have no experience with the other version of LS coils. Then believe it or not I ran a bead of silicone on each side between the coil and the intake runner. It took 5 minutes and they're not going anywhere. For coil1 and coil 12 there is no obvious spot between the intake so I cutoff the chimneys on the distributer caps to make room and made a bracket for each side to mount a coil. The spark plug wire just runs through the original wire chase under the intake. There is just enough room in there and they hide under the distributor decorative covers. That is why I was asking about the cam signal, I no longer have room for a pickup on the front of the cam unless I can find room for the coil that sits there. No one knows they are there but me. The 10 spark plug wires are about 12 inches long and loop around the plug boot in the head so that the plugs can be pulled without messing with the coils.

what kind of car is this in? With my SL I have 1/2" clearance to the hood insulation foam at the front of the engine. I lost 3/4" of clearance when I installed new motor mounts, I was not expecting that. I have no room on top of my engine for coils, luckily these round ones fit in the intake valleys.

My wife and friends scratch their heads but I have enjoyed this project, good luck with yours. All the info you need is there and the support always amazes me.

[V12r]

Hey Tinker Toy, would you mind posting your MSQ so that I can compare it to mine?

[Tinkers Toy]

I just resolved a plugged cat converter issue last weekend. totally plugged up and couldn't get over 2500 rpm. Now, wow, this thing roars but a new issue has cropped up. All that flow across my wideband sensor has caused it to do some weird things. It works great for 5 min and then it just shows full rich AFR at 8.0. I think it is overheating but it's not throwing any codes that I recall. I'm working tonight on moving it out of the direct flow with a spacer. long story but I just don't trust my tune in any way to publish it right now. let me get this O2 sensor issue corrected and tidy up my tune. then I'll be happy to post my MSQ. give me a week.

[Tinkers Toy]

my car runs ok on this tune but I'm still working on it

2015-09-01_20.28.32.msq