84 GPZ1100 dual spark / wasted spark 2 tach

[jydog]

Help, I've got this far.

Microsquirt v3
two tach signals hooked up vr1 vr2 hooked up to stock gpz sensors and run though tachref and I got both signals ok. I reloaded MSII 3.87 code and set igniton setting as follows

Advanced Igniton options
trigger wheel teeth = 0
missing teeth = blank
camm tooth =0
iat spart retard = 800
full iat retard = 1500
FET output delay =0
vr input delay = 0

Base Igniton Settings
trigger offset = 24 ( vr sensor for cyl 1 and 4 is aprox 24 BTDC )
skip pulses = 3 ( I have no idea why, I copied somone elses config with a honda 4 cyl ) is this right?
predictor algorithm= last interval
alpa = N/A
beta = n/A
gamma = N/A
time mask = 0
cranking % = 50
after -start % = 70
normal running = 25
check tach sync opt = check always
ignition input capture = rising edge
crank trigger = calculated
coil charging scheme = standard charge
spark output = going high

When I crank the bike to test the RPM, the signal bounces all over the place very eratic. What do I need to change ? I looked for an example of the same setup but could not find anyone who had dual spark \ wasted spark running with vr sensors. Is it not possible?

[dontz125]

How are you driving the coils?

[jydog]

I havent thought about that part yet. I am thinking about just using the pickup signals for now and going fuel only. If I can share the signals with the ignition module that is currently in place that is. Then when I would like to switch over and control the ignition I will be half way there.

[jydog]

Does anyone have a running dual trigger setup with stock vr sensors running? Everyone seems to be having problems with this and end up switching to some other trigger method. I havent found one good running example. My tachref program pics up the signal but Tuner studio logging shows it all over the place. If anyone has seen a running example please point me in the right direction, I have been looking and know how to use the search button.

[alan_3301]

from what I understand, if your are running dual spark mode, your trigger offset needs to be a negative number.
instead of 24 degrees try (-360 + 24) = -336degres.

adjust cranking pulse tolerance up to 75% or higher to see if you get a steady cranking rpm.

[UJM]

from what I understand, if your are running dual spark mode, your trigger offset needs to be a negative number.
instead of 24 degrees try (-360 + 24) = -336degres.

adjust cranking pulse tolerance up to 75% or higher to see if you get a steady cranking rpm.

I found this post and am sorry to see it was not followed up on.

My bike is a 1981 Suzuki GS1000 that had similar dual pickup coils, the rear coil was for cyls 1-4 and the front one for 2-3. There is a piece on the end of the crank with one tooth that turns to generate the signal- which is what Suzuki calls it in the shop manual, a signal generator.

They had a common ground wire, so I replaced the wire with a 4 wire shielded cable so each has an independent ground, and ran that back to the Microsquirt, where 1-4 was wired to VR1 and 2-3 to VR2. I have a coil driver box with two x 220 ohm resistors feeding two logic level transistors. I see spark at plugs 3 and 4 (on different coils) when I plug other plugs into them. The reason I went this route is because I could not get a good signal from the 1-4 coil on the Opto in fuel only setup.

I'm using a V3 unit, and version 3.83. I have the ignition setup as dual spark, dual tach inputs, with M=0. I think all of my settings except BTDC are as the OP has listed for his GPZ 1100.

The pulse tolerance when set to 85% helped smooth out the gauge reading.

I have not found any timing settings that allow the bike to fire and start. My native specs are 17 deg BTDC at under 1500 RPM, not the 24 the OP had, I've tried 17, -17, 0, and -343 (360-17) for both the basic ignition setting as well as the dual spark setting. The best I've gotten are a couple of small backfires. I'll attach an MSQ from today.

[UJM]

I used the tachref program tonight and didn't realize there is no way to save the output. I did a couple of screen caps and tried to splice them together. If I can attach a JPG, I'll do so.

There is some distortion about halfway through where I tried to splice two pics together. The red line is from the 1-4 pickup and the yellow one is from the 2-3 pickup. The red one seems more uniform. I'll have to read and see what they are supposed to look like, and if they are to overlap at all.

[alan_3301]

I have not found any timing settings that allow the bike to fire and start. My native specs are 17 deg BTDC at under 1500 RPM, not the 24 the OP had, I've tried 17, -17, 0, and -343 (360-17) for both the basic ignition setting as well as the dual spark setting. The best I've gotten are a couple of small backfires.

I recently found on mine that trigger offset has no effect on cranking ignition timing, and I was getting occasional backfire and thats it.
I am going to try moving the pickup in relation to TDC to try and get it to fire where it should.

I think I saw in the docs that if it loses sync it uses the ignition input for timing, but what is you don't have a cam and crank wheel. It will never sync right?
Sorry to hear you are having problems, I had thought about getting the v3 microsquirt to see if it helped, but I'd be really sad if I was having the same problems.

[UJM]

Hey, this place is not a total ghost town!

I have since abandoned the dual trigger idea and am awaiting a 24-2 trigger wheel that will work with the stock 1-4 cylinder VR pickup and press on to the stock advance unit (the tooth will have to be ground down). I have removed the 2-3 pickup and associated wiring. The 1-4 wiring is in a shielded cable, with the shield being grounded. I should have the wheel here by the end of the month.

Here's a drawing:

[nakedninja900]

jydog
I think you have done the right thing by getting rid of the second pick up, I am running spark only at the moment on my ZX9r motor (very similar engine).
Try and get the trigger wheel welded on at TDC or as near as, it will make your cranking advance easier to tune. I ended up breaking my starter chain ! So moved the wheel to TDC. (I thought it was at TDC but turns out it was 8deg BTDC)
Here's how I fitted my 36-1 wheel I bought from "trigger wheels.com"