Launch limiter method: None - still cuts spark?

[jesse408]

Using MS2 v 3.0
I just want to use the launch retard function without cutting any sparks. If I set the limiter method to "none", spark still cuts and tuner studio retard gauge begins bouncing back and forth from what I have set in my regular spark table (32°) to what I have set in lauch control ( -15°) instead of a steady, smooth -15°.
Is this normal, or did I build the circuit incorrectly/diode backwards?
If the pics load, the 4 logic sparks are near top right of proto area and the launch control is near the bottom, with a tach output somewhere in between.

20130822_203837-1.jpg

20130822_203944-1.jpg

[jsmcortina]

[jesse408]

Camaro_2014-04-18_10.43.46.msq

no cut 2014.msl

Thanks for looking.
If watching the main dashboard you can see the timing jump back and forth and the engine is definitely cutting sparks.
Is this normal, or possibly I may need to do some additional work on the board???

(This is a MS2 3.0 board and 3.3.1 firmware using PEO/JS7 mod on daughter card and grounding input scheme)

[jesse408]

I removed the MS from the car and double checked my work (again).
It appears that the circuit is built correctly. This is the circuit used.

lowinput2.gif

While the MS was out, I tested it on the stim to eliminate the cars wiring as a possible problem.
The problem was happening on the stim as well.

[jesse408]

I'm using LS coils in waste spark.
Looking at the board modifications for spark "D" in the manuals, I notice that it does not show, nor did I install a diode in the spark "D" cicuit beween the transistor and resistor (like D14, D15, and D16.).
Could this cause an issue while on launch control due to some kind of feedback?
Here is the circuit I used.

ABC_Spark5_3.0.gif

[jsmcortina]

I don't think it is cutting spark, it is just applying the 15ATDC timing that you have asked for.

James

[jesse408]

So then what you are saying is that the MS only retards X of Y Sparks instead of all of the sparks?

[jsmcortina]

So then what you are saying is that the MS only retards X of Y Sparks instead of all of the sparks?

No.
It retards the timing when in launch mode and above the lower limit - as per you settings. Then the engine loses a ton of power due to the ATDC timing and the RPMs drop. Timing the returns to normal, the engine revs up and the process repeats.

From the log it appears to be working exactly as expected.

James

[jesse408]

I guess I was hoping it would stay retarded and not return to normal timing until after the button was released instead of cycling between my timing table and my launch control setting while the Launch button is pushed.

[jsmcortina]

Try less retarded timing or more throttle.

James

[jesse408]

Thank you.