Tach output?

[JIrons]

I have an ms3 setup for fuel only need to know if the tach output with a 12-volt signal from a dual coil ignition system goes to pin number 24 on the main board?

[JIrons]

2016-11-08 14.05.07.jpg

2016-11-08 14.05.51.jpg

Is this the right setup for fuel only using the tach output from an electromotive hpv-1 ignition system for RPM signal instead of the negative side of a coil? The jumper on D2 is just for the jimstim.

[Matt Cramer]

Are you trying to run fuel only?

[JIrons]

Yes for now, but the manual is unclear about using the tach output from an ignition system vs the negative side of a coil. The tach output from the hpv-1 is 12v. I'm not getting an rpm signal from the jimstim or the tach output so I'm trying to make sure I have everything right to better pin point the problem.

[JIrons]

Also all the other sensors seem to be working properly. I'm getting tps, o2, clt, mat readings.

[jsmcortina]

I have an ms3 setup for fuel only need to know if the tach output with a 12-volt signal from a dual coil ignition system goes to pin number 24 on the main board?

That's the tach INPUT.

James

[JIrons]

Okay, but is this the right board setup for that type of tach signal?

[slow_hemi6]

Board seems ok to me. It is set up for opto input. If you are triggering off your HPv-1's geen wire, without the amplifier then you need the D2 jumper in place. The VR input is the most common used input these days for anything but a coil- input. Note the green wire is not the same as a coil- trigger it is more like a Hall with 12v pullup input. If you have the amplifier then it is similar to a coil- input.

[JIrons]

I was trying to trigger off the hpv 1 tachometer drive output terminal. There isn't a green wire. I'm not sure what you mean by amplifier? So going back to vr jumpers would be a better choice?

[slow_hemi6]

I just read the HPV-1 pdf and it says green wire is the 12v tach signal, but that may be the colour of the wire on the amplifier module itself. Amp module is shown in the pdf but is not required for triggering your MS. You need to test that tach out terminal while cranking to see if it is working. If so then you could try setting it up as per a hall sensor with pullup on the VR input as shown in the manuals or trace the signal through the opto input to fault find. Still need to see a msq from you to ensure you have not simply misconfigured the input.
http://www.msextra.com/doc/pdf/html/MS3 ... .4-75.html
http://www.msextra.com/doc/pdf/html/MS3 ... 4-190.html

[JIrons]

Thank you so much for the info. I have checked the voltage on the tach output. It's 12v when the ign is turned on. I will run a msq and get back to you.
Jeff

[JIrons]

2016-11-12_14.30.56.msq

Luke,
Here is the msq. if you could please take a look.

[slow_hemi6]

I can't see any settings error there that would cause an issue.

[JIrons]

Do you think I should remove c12 and c30? And the xg1 to xg2 jumper? Switch tachselect to vrin, and tsel to vrout? Jumper both d1 and d2?

[slow_hemi6]

If you do change over to the VR input with the jumpers then that takes all the opto circuit out of the picture. So no diode jumpering, capacitor removal or xg1-xg2 removal needed.

[JIrons]

What the 24v zener on d2?

[slow_hemi6]

Yes, look at the schematic I posted changing to VR input isolates the whole opto side.

[JIrons]

Oh I see now. The link wasn't exactly clear. So just to clarify, d1 and d2, xg1 to xg2 are all part of the opto circuit and basically taken out of the circuit by using the vr jumpers?

[slow_hemi6]

correct.

[JIrons]

SUCCESS! I put the vr circuit back in play, but because I had changed TS setting to alpha n while I had the opto circuit in place I now have rpm! I hooked everything back up to the engine and it STARTS! Everything is working great..... Now to start tuning....
Luke thank you so much for taking the time to explain a few things to me. I really do appreciate it.
Jeff