dual vr wiring

redracer · Post by **redracer** » Mon Dec 10, 2007 1:32 pm

Hey all, I've got an interesting question about wiring up my uS. Every time i crank the motor, the Microsquirt powers down instantly. I've done the basic troubleshooting of isolating the grounds and power directly to the battery and also jumping the battery to a larger one to confirm enough voltage was available.

Here's my basic layout:

Honda motorcycle style all stock sensors
4-stroke 4-cylinder
12 tooth VR on crank
1 tooth VR on cam
cam tooth index 130.5 degrees

I wired up all the sensors and when just powered on, everything is reading fine (tps, intake temp, etc..). I then wired up the crank VR to VRIN1 + and - ... i got tach results when cranking (with the configuration not set to cam sensor). Then i wired up the cam VR to VRIN2 + and VRIN1 - (as i found in the docs) and configured the software for M-0 with falling cam trigger. This is when i suddenly got the shutdown issue.

The interesting thing, is i disconnected my cam VR from the VRIN 1 - wire and the microsquirt stays up... just no tach signal, of course.

Any ideas of what i'm doing wrong?

Thanks.

Robert

Post by **Bruce Bowling** » Mon Dec 10, 2007 2:10 pm

redracer wrote: I wired up all the sensors and when just powered on, everything is reading fine (tps, intake temp, etc..). I then wired up the crank VR to VRIN1 + and - ... i got tach results when cranking (with the configuration not set to cam sensor). Then i wired up the cam VR to VRIN2 + and VRIN1 - (as i found in the docs) and configured the software for M-0 with falling cam trigger. This is when i suddenly got the shutdown issue.

A couple of things to check:

1) Make sure you are running V2.882 or higher embedded code, this is extremely important with the MicroSquirt. You will know this code version because you will have to set the ECU type before you can proceed...

Al posted this code here in this forum a few weeks back.

2) Make sure that the hall sensor is not causing a direct short of the 5V power supply (Vref), if you are using this configuration. Hall sensor's emitter terminal should be grounded, the collector pulled up to Vref thru a 1K resistor, and this junction goes to the VR2in+ terminal.

- Bruce

redracer · Post by **redracer** » Mon Dec 10, 2007 2:50 pm

Thanks, Bruce, for the response.

Ya, I'm pretty sure I'm not running the latest release. I haven't updated it at all so it's running the original 1st run shipping rev. ... It's been sitting half wired for a while, getting married somewhat paused the project until recently.

As for the wiring, these are two wire VR sensors (to the best of my knowledge) , so they aren't tied to the 5v supply. But, yes, that was my thought too when doing my inital trouble-shooting, but by even completly cutting the 5v lead from the uS to the sensors, the problem persisted.

If it helps any, here is the factory wiring diagram.
http://www.stellhornracing.com/r12xmanu ... ce20-3.pdf

I'll get this thing updated and give it another try, tho.

Thanks again!

Robert

Bernard Fife · Post by **Bernard Fife** » Mon Dec 10, 2007 3:00 pm

Robert,

The latest release code is 2.881. To get the 2.882+ that Bruce mentions, you need to go to the beta release page here: http://www.megamanual.com/ms2/betacode.htm

Lance.

Post by **Bruce Bowling** » Wed Dec 12, 2007 5:31 pm

redracer wrote: Ya, I'm pretty sure I'm not running the latest release. I haven't updated it at all so it's running the original 1st run shipping rev. ... It's been sitting half wired for a while, getting married somewhat paused the project until recently.

Also, when you update the code and reload your old MSQ, be sure that you check the ECU_TYPE afterwards to make sure it is set to MicroSquirt. There is question whether this one variable will get set properly from an old MSQ file, so be sure to check this directly. This setting affects the use of the second VR input directly, this is why this is critical to set right...

- Bruce

redracer · Post by **redracer** » Fri Dec 28, 2007 10:09 am

Ok, so i got it updated to v2.882 ... and fixed a wiring glitch i found (one vr sensor wiring was reversed) and now the microsquirt stays online and actually will show the proper RPM when cranking. Yay!

But, now i've got a couple new problems. Under v2.883, none of my sensors are registering at all. TPS, MAP, Temp, etc... all non responsive. Also, when not cranking the rpm meter will kick from 0 to 8,000 instantly and then back again about once a second. When i flash back 2.862 everything starts working, (minus the cam trigger of course).

Any ideas?

Thanks!

redracer · Post by **redracer** » Fri Dec 28, 2007 10:30 am

oops... never mind on that last tidbit.. I had looked for the microsquirt ecu type setting but hadn't found it. I just read that my symptoms are done to tell me that i hadn't set it. I will find it, set it, and give it a try again.

Thanks again, everyone.

redracer · Post by **redracer** » Sat Dec 29, 2007 9:57 pm

Well, i did a fresh install of megatune, updated the microsquirt to 2.883b and dropped the associated files into the car1 directory and then configured everything by hand again, including the type setting... and loaded them into the microsquirt.

Now, i don't have the warning 0 - 8000 - 0 - 8000 simptom anymore as expected by the type bieng set. but now i get absolutly nothing on the gauges in megatune. no battery voltage, nothing. all i see is in the ready area, a type is set message. when i power up the microsquirt i get the two beeps and that's it.

what am i doing wrong? anybody? am i still bieng stupid on something?

thanks.

Robert

redracer · Post by **redracer** » Mon Dec 31, 2007 7:27 pm

After several hours today of trying different things, i'm a little closer, but still having cam trigger issues.

I had to re-install megatune on a different (older, more reliable) laptop, re-update the microsquirt, and start fresh with the configs... that finally got me some results from the sensors.

Basically i'm fighting with the advanced ignition settings. I think the rpm's show right when the Skip teeth = 2, no matter what the Trigger Wheel Teeth is set at. And, anytime i turn on the cam trigger setting, the rpm gauge will flip down to zero for split seconds while cranking... and the frequency it happens depends on the number of teeth in the trigger wheel teeth option. At no point did i get reliable output with cam trigger option set.

Attached is my efforts of today. I was all over the board with playing with settings, so i wouldn't be suprised if it makes no sense.

Post by **grippo** » Tue Jan 01, 2008 9:20 am

This is a complicated setup because you have no missing teeth on your 12 tooth wheel, plus a cam synch. The dual spark options allow this case with a crank synch, because that is the way I have usually seen it (a flywheel with a hole or special tooth welded underneath the tooth ring). But you have a cam synch, which would probably be ok for a 2 cylinder, which would give you sequential. But you have a 4 cylinder, but microsquirt only has 2 outputs, so you must of necessity have wasted spark. So before we proceed further with this, I need to check out your msq on the bench and see if it is possible to work.

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