Input signal disappears. Can anyone help me please

[MagnaZT]

Hello everyone. I am a bit perplexed with my input results. I am running a MicroSquirt unit(Black Board) version V2 with 2.89 code. I was originally using it for both Ignition and Injection but because of the configuration of the motor, a V2-45degree with no tooth wheel, I found it simpler to use the MicroSquirt for injection only. The motor at this point starts remarkably well but as it runs the RPM signal disappears. It almost seems to be RPM sensitive but I am not sure of that. I have put a scope on the tech out signal line from the ignition module that I had purchased and it showed no missing pulses or pulses dropping out. I had Pin# 30 connected to that line and 31 to ground. I also reversed the wires Pin# 30 to +12 and 31 to the signal line from the ignition module and I also made a connection to the spark coil as recommended in MicroSquirt docs Coil to Pin# 30 and +12V to 31. All of these connections started the bike but had the same dropped RPM result. At 1 point in earlier installations I had tried to use the MicroSquirt's ignition and had set a bunch of parameters. Is it possible that those parameters may be messing up my RPM signal that microSquirt needs to run the injectors. SO I am looking for recommendations on what to do or look for. Or better yet, Is there any way to just disable the ignition side of the MicroSquirt. I have also sent with this post a copy of the last data recording I had done today. A pic is worth a thousand words. Any kind of response would be greatly appreciated. Thanks

[Matt Cramer]

Is it getting RPM from a coil or from a sensor? If it's a sensor, what kind of sensor?

[MagnaZT]

Thanks you for responding Matt
It's getting the signal from an ignition module primarily but I have tried both. In any case my signal is a 10 Vdc square wave. I have OScoped it to pin# 1 of the CPU it is clean there at 5Vdc Square. The problem is in the CPU. Hopefully I have something set wrong in the configuration. Do you have any thoughts on that??

[Matt Cramer]

If you suspect a CPU problem, could you please post a copy of your MSQ file? That way I can check if any settings are causing the problem.

[MagnaZT]

Hi Matt:
Thanks for responding. I had given up hope that anyone would. I sent the MSQ as requested and a new data log. I am getting my pulses from an ignition module, and in case you need to know anything else, let me run down the list of STUFF. The ignition module is a Daytona Twin Tec model 1005. It puts out a 10VDC square wave normally at 10V with 0V pulses. There are 2 pulses per cycle set (720 degrees). There are 2 injectors and they are low impedance with a flow rate of 120 GPH. I am using a GM 3 Bar Part# 12223861 for the MAP and a MPX4250AP for the Barometric Air Pressure. Standard GM Manifold temp gage, the engine temp gage is my own but it is much like the GM. I'm running 2.89, Black board MicroSquirt (I think that makes it a V2??). Also, keep in mind my first post and how I traced the signal all the way back to pin#1 of the CPU and that it was clean to that point. I think that's it but if there is anything else you want to know, Just ask and again Thank-You very much for all your help. I will be sure to keep an eye out for your next post so that I may respond sooner.

[Matt Cramer]

Ok, there are two possibilities here if the pulses from the Dyna are all equally spaced. (If they're unequally spaced, let me know; we may have to use some other settings.)

One, the signal is barely strong enough to trip the optoisolator. If that is the case, occasionally you may lose a couple of pulses that the processor just plain won't see. If that is the case, the appropriate remedy would be to use the Hall offsetter circuit and bring the signal in on the VR conditioner. This does not need as strong a signal.

Two, there's a bit of a noise issue or the signal changes unusually fast. If that is the problem, adjusting the Next Pulse Tolerance setting ought to clear it up.

[MagnaZT]

OK first. The pulses are uneven. 0 deg, 315 deg and then 405 deg (0=720 deg total) Typ for Harley with 45 deg cylinder offset. It is a it is normally a 10V high with 0 v pulses. I have checked it with an Oscope at the input to the CPU at pin#1 it is a strong signal ( I can see the rpm on mega tune jumping and see a clean signal at pin #1 on the CPU.) OH forget noise. All wires to and from the MicroSquirt are double shielded and grounded. I like that VR thought you had. But I could do 1 step better. What if I put 1 VR on the bike at the crank and place a single tab. A 4 cycle engine would create the appropriate 2 pulses per 720 degrees. What ya think?? OK Let me know what ya think. Thanks Mat

[Matt Cramer]

I think it's the oddfire split that is causing the problem then. Could you feed it the signal from one of the Dyna's two pickups on the tach input instead? You'd have to tell it you have a one cylinder to get the correct RPM but this should get around the noise issue.

[MagnaZT]

OK I think you mean from 1 of the 2 coils. Yes. OK I did that and changed from 2 cylinders to 1. But it said 2 squirts was no good. Something about PWM being to small. So I changed it to 1 squirt. Then it said alternating wouldn't work so I changed that to Simultaneous. I started the bike and it started very ruff and wouldn't stay running. I tried changing the required fuel up a bit. It smoked a bit so I tried setting it a bit lower no change. I tried getting a data log but it wouldn't stay running long enough for me to hit the button. I will try it again this weekend. I n the mean time you never did say what you thought about 1 VR at crank. It would give us 2 pulses every 720 degrees and they would be evenly spaced! What ya think.

PS Don't quit on me now. Thanks

[Matt Cramer]

The add on crank trigger would work great. One tooth is perfectly fine for fueling. If you go with a missing tooth wheel, you could get spark control too - you might want to make it so you have the option of running multiple different wheels.