No ignition signal at MSII - MSD Pro-Billet Dizzy

[redjet]

Hi Guys!

My Set up:

BBC normally aspirated 496
MSD Probillet Dizzy - Verified resistance reading is in spec between 500 and 700 ohms per MSD
MSD6AL - Checked Coil and box functionality by touching white wire to ground per MSD
MSII, v3.57 board running version 2.889 manufactured by DIYAutoTune.
Q16 installed, J10 jumped to IGBTIN
J1 - pins 3 to 4 are jumped for VR out
JP1 - Pins 1to 2 are pumps for VR in
36 pin harness from DIYAutoTune with the gray shielded wire stripped and connected as follows: Shield connects neg VR wire to pin #2 and inner wire in white jacket connects positive VR wire to pin #24. Pin 36 is connected to white MSD6AL input.
R52 and R56 have not been adjusted from factory settings.

MegaTune ignition settings:
Ignition Input Capture: Rising Edge
Cranking Trigger: Trigger Rise
Coil Charging Scheme: Standard Coil Charge
Spark Output: Going Low (Normal)
Dwell: 25.5
Trigger Offset: 15

Current Conditions:

Cranking the and getting no strobe from the timing light. Followed this by watching the Tach gauge in MegaTune while cranking and it does not show any signal. So it appears that I am not getting or recognizing the signal from the MSD VR sensor. I have been unable to set initial timing with no strobe from timing light while cranking.

Request:

I have read the Manual and Tech bulletins on DIYAutoTune and am stumped. If you guys tell me that my setting are all correct; I will take everything apart again and re wire from scratch because I have a missed connection. Are there ways to check the functionality of the VR circuits on my MSII with a digital multimeter. I don't have a Stim as I purchased my unit from DIYAutoTune and made the assumption that it arrived on my doorstep functioning. I will purchase one if I must, but wanted to check with the knowledge base first.

Your help is greatly appreciated!

Best regards,

Jereme

[Matt Cramer]

If you could post your MSQ, I could check a couple other settings that might be killing RPM. Also, can the board get an RPM signal on the Stim?

[redjet]

Hi Matt,

I will post in a few minutes. I am on my desktop and it is on my laptop. I don't have a stim. I am currently wrestling with the tackref application trying to get it to work with my laptop. I am considering moving to tuner studio as it appears to have this capability without an additional application.

Thanks,

Jereme

[redjet]

Here is my msq.

[Matt Cramer]

No obvious RPM killers in the MSQ - try giving R52 and R56 six turns counterclockwise.

[redjet]

Very Nice! I went the full 6 turns and the MSD started singing! Too much of a good thing maybe...? I backed both pots off 1.5 turns that the MSD seams a little happier.


I also found that I had the distributor two teeth off.

After I fixed that I noted that when I crank the engine the Tach in Tuner Studio will show ~300 RPM then drop to zero then back to 300 RPM. I am trying to log some data using tuner studio, but am still figuring out how to get the diagnostics tab activated...

I am also trying to adjust one pot at a time in a serial manner to see if I can get the tach signal to show realiably on Tuner Studio.

Any suggestions?

Thanks,

Jereme

[redjet]

I just put one full turn (CW) on R56 and it stabilized the Tach signal. I'm gettin' close to starting this thing! WooHoo!

[redjet]

I'm back. I have a tach signal but it is really unstable. When I start the engine I will get sporadic RPM spikes up to 14K RPM. This appears to go away after the engine catches and begins to idle. The real problem appears to be the regular loss of the RPM signal. Please see the attached data log.

R56 if fully CCW
R52 3.5 CW turns in from fully CCW.

To try to limit the RPM spikes I increased the Time Mask to 7msec and over multiple starting events I did not see that this had any effect. I also reduce the Percentage mask to 10% based on another post that appeared to have a similar problem.

Also having a heck of a time setting initial timing with the intermittent timing signal driving wild swings in the advance curve.

Any help that you can provide regarding the Tach Signal would be appreciated.

Thanks,

Jereme

[redjet]

Hi Matt,

I have changed my firmware to MSIIextra and am moving to that forum. Thanks for your help.

Have a Happy Thankgiving!

Jereme