Jstim w/ MS2 v3, no tach (VR)

[olaaf]

Hello

I have a freshly built V3 board with the VR conditioning circuit. I’m planning to use it on a ford 4.6 without EDIS, getting the crank trigger directly and firing the coils directly. I can’t get any tach signal from the Jstim (with latest firmware, purchased about 3 weeks ago from DIYAutotune).

I have DIP pin 3 set to ON, jumpered tach from Hall (square) to VR, and tried both regular and inverted tach signals (DIP pin , and tried both 5v, 12v, and no pullup voltages.

On the MS board I followed the instructions on the DIY autotune ford tech article and did this:

• Jumper TachSelect to VRIN
• Jumper TSEL to VROUT

I’ve also turned the trim pots on R52 counterclockwise (like 10 full 30 turns) until it clicks, and turned R56 counterclockwise until it “barely” clicks (it’s a very, very soft click). I’ve pretty much tried the trim pots in every setting.

I’ve been reading here http://www.megamanual.com/ms2/vradjust.htm

But not sure what to try next..

Thanks in advance,
olaaf

[racingmini_mtl]

Is your MS configured for 36-1? The JimStim setup for a VR signal should be a 12V pull up. But you should also be able to get a tach signal with the jumper set to the square wave mode and with a 12V pull up. And from what you say, the jumpers on your MS board are correct.

Have you done the tests described here to make sure the JimStim tach signal is ok?

Jean

[olaaf]

Hi Jean

thanks for the response. Yes, in MS TunerStudio i have set the tach settings for toothed wheel, and under trigger set for 36-1, 40BTDC, and crank wheel. I just tested the CPU on the Jstim with the instructions in the link you provided and the LED flashes when i turn RPM fine. (i purchased the JStim pre-assembled). the other pots work (coolant, wideband O2, etc.)...

anything else you think i could try?

thanks very much,
olaaf

[HidRo]

I remember having some issues with this, and in the end, I was missing a jumper somewhere. I don't know where, but as you mentioned you tried it both, I'm not sure. Primary tach or something?
You could post up a picture of your JimStim setup, just to see if something is off.

[olaaf]

hmm. i'm pretty sure it's not a Jstim problem, as the tach drives the LED in the test mode.. i think i should just confirm i have continuity from the tach pin by the jumper the the DB37... after that, it's all in the MS2 board... but i don't know where to start..

[HidRo]

I also tested the jimstim, and it was fine with the wire jumper, etc.
But I was missing a jumper, and I'm not sure it was for the primary tach, or something.
That is why I was saying for you to post a pic. Maybe just missing something easy.

[racingmini_mtl]

Please post your msq. This way we can see if you have some configuration issue.

Jean

[olaaf]

MSQ here

http://icedhay.com/images/crownvic/2011 ... .20.32.msq

picture of Jstim



thanks all!
olaaf

[racingmini_mtl]

That JimStim seems to be configured correctly for what you have in the msq. And there is nothing I can see in the msq that would prevent you from seeing RPM. But you need to change the MAP sampling angle to something less than 90 degrees in the 'General' settings. You should still see RPM but that would prevent you from having a correct MAP value.

Jean