Incrementing rpm signal!?

grippo · Post by **grippo** » Sun Sep 16, 2007 8:15 am

Are you satisfied that the tach input signal is not missing any pulses. I know it is hard to tell during cranking, but you are in the best position to tell this. The pulses may get closer and further apart as the engine turns, but the pattern should be consistent. I am just talking about the input signal pattern.

Does it look consistent with no misses ?

Are there any 0 rpms in the datalog ?

Are the rpms in the datalog reasonable ?

I don't need a datalog - just the answers to the questions.

The other thing you can try is to scope the input signal as it comes out of the VR or opto sensor circuitry and goes into the processor. Don't try to probe the processor pin - it's too tiny, put probe it on the other end. This should give a nice square wave of 0 and 5 V that makes it a lot easier to see a pattern.

As far as the voltage dropouts, you may have some bad grounds because the processor can run off a fresh 9V battery that you can buy in the grocery store. But the voltage into MS does need to be atove about 7 or 8 volts to work properly. Again you can scope this and see if it correlates with when the comms to MT drop out.

The Benz Master · Post by **The Benz Master** » Sun Sep 16, 2007 5:15 pm

the signal from the crank sensor does never miss !!

no 0 rpm, just the rpm jumping from 300 to 600 still (maybe the other day i just had a RPM lag factor higher than what i have now, keeping the RPM stable while cranking)

The datalog does show that voltage to MS sometimes drops to 7.4v while cranking

.... and i got a bigger battery than what's physicaly possible to put on the bike... would a 1 or 2 farad subwoofer condenser solve this problem?

I'll try somethings and i'll get back to you to see if it works ok

thanks a lot

The Benz Master · Post by **The Benz Master** » Sun Sep 16, 2007 8:56 pm

Tham.. i did'nt get one spark today, even before changing anything!

No RPM reading from MT at all

i dont really understand what's going on now.

So i scoped the vr sensor vs the irq (pin 14 on the MS2 daughterboard which should be the output from VR circuitry to the processor) and got something prety consistent that looks ok to me. Anyone knows for sure if this looks right? this same set-up was giving me sparks and RPM last wednesday...

grippo · Post by **grippo** » Mon Sep 17, 2007 9:13 am

This trace looks right - there should be a rising edge on the IRQ every time the VR trace crosses from above to below the 0 line. In fact, looking at the scope trace from Fri, Sept 14 the ignition output tracks with the VR input. So everything is functioning correctly. Now how consistent is it. If you look at many events does the ign output always follow the missing tooth on the IRQ trace. If it misses a lot then save the msq from this run (hit file, save before shutting off MS). If it doesn't miss except maybe 1 or 2 every great once in a while, then the plug should be sparking every time unless the injector drivers are blown out.

By all means use the subwoofer caps - Bruce recommended this a week or so ago on another thread.

The Benz Master · Post by **The Benz Master** » Mon Sep 17, 2007 10:02 am

The IRQ never misses a beat !!

but i do not get any spark output, neither do i get RPM signal in megatune anymore...

I'll try to reburn the software in the processor, maybe the voltage spikes got everything scrambled up and erased some data? I'll also source a woofer cap to get things smoother!

If then it does not work, i'll send in the MSQ

Thanks

The Benz Master · Post by **The Benz Master** » Mon Sep 17, 2007 9:43 pm

Alright, i've re installed with the latest code available and scoped the thing while dataloger was on, etc!

Seems like the processor does not "digest" all of the input signal altho it's spot on on the IRQ.

tha Delta T is 2/3 of the time at "0" meaning my signal might be noisy or something. Is the processor fast enough to detect voltage drops if the signal is not lost long enough to show on my scope? thuss, i look at a nice graph/signal while processor sees a lot of junk?

I still dont have a cap for the starter tho

grippo · Post by **grippo** » Wed Sep 19, 2007 12:41 pm

I tried your msq at a steady 240 rpm and got the same problem - no rpm, no output . I tried it with Skip_Teeth = 12, and got rpm and spark output, but the timing wandered quite a bit even though the rpm was constant. The problem with this setup is you can't do wasted spark with an odd no of cylinders. So I tried running it as if the wheel were attached to the camshaft as if 1 cylinder COP. This gave everything perfect, but no spark output.

I am puzzled by the last result. It may be a low rpm problem only - I just don't know at this time. It is something I will solve, but it may take a few days or it may take months given that I am working on so many other things. If this is a problem email me offline.

But note, if you are getting spark output on the scope, but the plug doesn't fire, then that is an electrical problem, possibly a burnt ignition driver.

The Benz Master · Post by **The Benz Master** » Wed Sep 19, 2007 4:50 pm

NO, no, absolutely no spark output on the scope

the MSD fires fine, i test it once in a while and it's perfect... just ground the white wire and remove it to make it spark.

I'll try it with skip teeth = 12 later tonight and i'll post the results

i will also try telling MS it's a 2 cyl and see if it works beter. If it does not work with odd number of cyl, it should work with 2!!

thank you

The Benz Master · Post by **The Benz Master** » Wed Sep 19, 2007 9:30 pm

Ok, i did'nt get any spark with the skip_teeth to 12 but i did get some at 3 set to 2 cyl and 2 skip teeth set to 6 cyl

I'm starting to think it's a problem with the number of tooth i have on my trigger wheel.

The 6 cyl 2 skip teeth yielded a constant spark output and when i scoped it, it showed to be good timing wise (set to skipteeth 3 ans 2 cyl, it seemed to wander like you mentionned it hapened at skip teeth 12, 1 cyl for you)

6 cyl using 3 teeths= fine, 2 cyl using 2 teeths = fine.... so does this mean i should go back to the single tooth that was used on my stock ignition sys?? seems that a few guys are running single cylinders on a single tooth set-up. I tought that by adding some tooths, i'd get a more precise ignition/fuel output.

P.S. some people stated that the MSD made huge noise and stuf in the MS... my scopes were as clear if the MSD worked or not and they are sitting right beside one an other with the coil bolted right under the MS box... might consider an other theory for noisy signals/power spikes...

The Benz Master · Post by **The Benz Master** » Wed Sep 19, 2007 10:52 pm

Ok... tried some diferent settings and set to two cylinders, skip teeth= 6, delay = 1 i get some spark but rather unusual... i get two of them at odd interval but relativley constant interval...

P.S. chanel 1 = crank sensor, chan 2 = spark output from MS.

i also get spark with same settings but set at 1 cyl but spark is rather random.

I think i'll try the one tooth setup but i'll need to crack the engine open in order to do it.... that sucks !!

grippo · Post by **grippo** » Thu Sep 20, 2007 4:31 am

I did some more testing and got your setup to work perfectly. I too was getting weird behavior trying different settings but basically you can't do odd cylinder wasted spark EXCEPT, for the case of 1 cylinder you can fool the system by setting it for 2 cylinder, 6 Skip Teeth, NOT Dual Spark, 15 deg trig offset. This setup worked, the timing was rock steady with no moving or misses, and gave the correct rpm also. The only other thing I set differently was the coil and spark durations which I had as 3 ms and 2ms. I know you are using 25 ms for each because of the msd, but if it doesn't work try changing this to something like 3 and 3 ms and see if this works at least on the scope. Then we will know what the problem is.

The Benz Master · Post by **The Benz Master** » Thu Sep 20, 2007 5:51 am

Tham, i dont understand why we get diferent results by using the same values... i absolutely cant get it to spark with 0 teeth delay.

might want to see what the diferences are between our MSQ's so i can dial it in to spark!

Thanks a lot Grippo, your help is really apreciated

grippo · Post by **grippo** » Thu Sep 20, 2007 9:02 am

The only difference I can see that might matter is that I did in fact use a Delay Tooth of 1 with trigger offset of +15. Can you try it with a Delay Tooth of 1 and if you can't move the vr sensor maybe adjust the trigger offset to make the spark come out the same. Actually, if you disconnect spark and fuel you really don't care where it sparks just so you get a spark, then we can worry about how to get the timing right. The other possibility is that the starting rpm is too low. The lowest I went was 240 rpm because I believe you were near this rpm. If you can't get it, I will test tonight with your exact msq and adjust it until I get it to work.

The Benz Master · Post by **The Benz Master** » Thu Sep 20, 2007 10:08 am

yes, i do have spark at 1 skip teeth but i do not get constant spark. I did not try it at 15 deg tho, whe i tried it it was 90 or 0 i think.

this is what generated the scope two post above.

I'll try it tonight.

And i've received my 1.6 farad capacitor so it might solve other problems too.

thanks

grippo · Post by **grippo** » Thu Sep 20, 2007 3:44 pm

I tested with Delay_Teeth =0 and ran trigger offset from -75 to +75 deg and all worked perfectly. But I had the new v2.88 installed, so I went back to v2.873 and there were misses all over and the rpm read 350 when it should have read 240. Went back to v2.88 and all was well again.

So hopefully if you load v2.88, which I just released on the microsquirt forum under Gebneral Info, this may solve your problem. You will need the new ini, but after it starts up you should be able to open your existing msq file, then set the ECUType =1 for MSII, check the data, make a new msq (same as old but with proper ECUType added), reboot, and hopefully you will see sparks.

The Benz Master · Post by **The Benz Master** » Thu Sep 20, 2007 9:38 pm

Ok, tonight's tests were a bit deceptive!! i did get sparks all the time but they were never all there or the timing was off by at least 90deg before wandering to random sparks.

can you ship me your msq file where you got constant spark timing??

If it does'nt work, will a 1 tooth set-up work beter? the stock single tooth is still on the flywheel so i could open the engine and put the sensor back to it's original place.

I need to get the thing running before winter cuz i need it to go in daytona next march.

P.S. 1.6 farad cap took care of the voltage drop problem while cranking... i did'nt get a single reset tonight

grippo · Post by **grippo** » Fri Sep 21, 2007 4:19 am

Yes I will send you my msq tonight. The single tooth should also work - but timing accuracy is not as good as you can get with a toothed wheel. This should work, and we should spend a little more time to resolve it. Perhaps you can also post your msq from this last run where you got sparks using v2.88. Also, can you give me an estimate of the rpm range - at roughly what rpm does it fire ?

grippo · Post by **grippo** » Sat Sep 22, 2007 5:46 am

Here is the msq which works for me at 240 rpm.

The Benz Master · Post by **The Benz Master** » Sat Sep 22, 2007 11:53 am

I think that the rpm i got (when it was steady was arround 360)

I always got spark with v2.88, but just not right!

The Benz Master · Post by **The Benz Master** » Sat Sep 22, 2007 8:47 pm

Ok, a lot of diferent things from your msq, not sure how they affect spark output but timing seems to be off just like in mine !

1st, set to uS instead of MS2
Spark going high instead of going low
spark/dwell duration
skip teeth
deg F instead of deg C
etc

Ok, so what i did is change ecu type to MS2 not to fry anything and i tried it. always get two sparks at what seems to me 120 deg late of tdc.

then i set it to going low cuz MSD wont spark ok set on going high.. and the first spark seems ok and second seems still 120 deg off. It should be the waisted spark that is off, not that it maters that this one is off, but i'm not convinced the explosion spark is all that well timed if the other one wanders. And thinking about it, explosion spark should not be at tdc cuz skip teeth =1 in your msq as well as 15 deg trigger offset.

P.S. i dont remember exactly where i've seen this but there was a page showing what crank signal vs output should look like... i,m trying to find it to see exactly where the spark should be compared to crank sensor signal with x skip teeth and trigger offset.