Sync loss 13B rotary

General support questions and announcements for MS3. See also MS3 manuals.

Moderators: jsmcortina, muythaibxr

Re: Sync loss 13B rotary

Postby muythaibxr » Sat May 07, 2016 6:10 am

The non-resistor plugs could definitely have something to do with the problem too.

I would start by changing those out with resistor type plugs, and if it doesn't go away, fix the grounds.
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.

:msq:
muythaibxr
Site Admin
 
Posts: 8096
Joined: Thu Oct 14, 2004 12:48 pm

Re: Sync loss 13B rotary

Postby arran » Sat May 07, 2016 9:21 pm

I think I will have to look at what plugs to change to, the BR10EG do look to be a good option for a rotary

I moved rev limiter to 7000 to test during another short drive today, no sync loss.

I note that the circuit that is loosing sync according to the composite log is the 2 teeth wheel. This is connected to the MS3's VR conditioner (not the 3x). There is no reason that I should swap the 24 and 2 tooth wheels over?

Also, in the MS3 hardware manual, section 5.2.2 I have read that for high RPM a series resistor can be installed:
inline resistor.JPG

Should I perhaps do this?

Arran
RX7 Series 2 13B Turbo. Megasquirt 3 with 3X Expander and V3 CPU. Firmware 1.4.1
Knock module, twin EGT, real time clock, WBO2, full sequential fuel and spark
http://web.aanet.com.au/arran
arran
Master MS/Extra'er
 
Posts: 585
Joined: Mon Oct 29, 2012 2:34 am
Location: Brisbane Australia

Re: Sync loss 13B rotary

Postby jsmcortina » Sun May 08, 2016 3:18 am

arran wrote:I note that the circuit that is loosing sync according to the composite log is the 2 teeth wheel. This is connected to the MS3's VR conditioner (not the 3x). There is no reason that I should swap the 24 and 2 tooth wheels over?

You must be mistaken here. There's no way the engine would run if you had them swapped.

James
I can supply, repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: viewtopic.php?f=104&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
jsmcortina
Site Admin
 
Posts: 34069
Joined: Mon May 03, 2004 1:34 am
Location: Birmingham, UK

Re: Sync loss 13B rotary

Postby muythaibxr » Sun May 08, 2016 5:30 am

Also the resistor should only be needed with a high tooth count wheel.
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.

:msq:
muythaibxr
Site Admin
 
Posts: 8096
Joined: Thu Oct 14, 2004 12:48 pm

Re: Sync loss 13B rotary

Postby arran » Sun May 08, 2016 3:31 pm

Thanks for challenging me on that. You are correct, I went down to the car and performed a continuity check from CAS plug through to the MS DB37.

The two tooth wheel is indeed connected to the MS3X, and the 24 tooth wheel is connected to the MS3.

So if I'm going to be adjusting any trim pots it will need to be on the MS3X.


jsmcortina wrote:
arran wrote:I note that the circuit that is loosing sync according to the composite log is the 2 teeth wheel. This is connected to the MS3's VR conditioner (not the 3x). There is no reason that I should swap the 24 and 2 tooth wheels over?

You must be mistaken here. There's no way the engine would run if you had them swapped.

James
RX7 Series 2 13B Turbo. Megasquirt 3 with 3X Expander and V3 CPU. Firmware 1.4.1
Knock module, twin EGT, real time clock, WBO2, full sequential fuel and spark
http://web.aanet.com.au/arran
arran
Master MS/Extra'er
 
Posts: 585
Joined: Mon Oct 29, 2012 2:34 am
Location: Brisbane Australia

Re: Sync loss 13B rotary

Postby arran » Sun May 08, 2016 3:32 pm

OK, thanks

muythaibxr wrote:Also the resistor should only be needed with a high tooth count wheel.
RX7 Series 2 13B Turbo. Megasquirt 3 with 3X Expander and V3 CPU. Firmware 1.4.1
Knock module, twin EGT, real time clock, WBO2, full sequential fuel and spark
http://web.aanet.com.au/arran
arran
Master MS/Extra'er
 
Posts: 585
Joined: Mon Oct 29, 2012 2:34 am
Location: Brisbane Australia

Re: Sync loss 13B rotary

Postby arran » Mon May 09, 2016 6:47 am

Reviewing my Crank and Cam hardware and software setup, there is a question about the inverting or non inverting config on the base board.
In this thread:
http://www.rx7club.com/megasquirt-forum ... as-983587/

Ken states:
You should probably switch back to using the rising edge of both CAS signals again. That is assuming you have VROUT wired to TSEL. not having that right will probably cause sync loss above 4000 RPM.

In my setup, TSEL is connected the inverting output
inverting.JPG


I have both Crank and Cam on rising edge. Is this a problem? Should I change the Crank CAS signal to non-inverting? Can this be affecting the CAM signal which is handled by the MS3X? Assume I'd need to reset the timing calibration ......

Any advantage using the zeal daughter board?

Arran
RX7 Series 2 13B Turbo. Megasquirt 3 with 3X Expander and V3 CPU. Firmware 1.4.1
Knock module, twin EGT, real time clock, WBO2, full sequential fuel and spark
http://web.aanet.com.au/arran
arran
Master MS/Extra'er
 
Posts: 585
Joined: Mon Oct 29, 2012 2:34 am
Location: Brisbane Australia

Re: Sync loss 13B rotary

Postby muythaibxr » Mon May 09, 2016 1:21 pm

It could cause edges to overlap in some situations when they shouldn't.
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.

:msq:
muythaibxr
Site Admin
 
Posts: 8096
Joined: Thu Oct 14, 2004 12:48 pm

Re: Sync loss 13B rotary

Postby arran » Mon May 09, 2016 5:03 pm

Right, I'll swap to the non inverting vr sensor output on the base board (24 tooth crank wheel).

I can't find the info right now, I'm sure it will be in the manuals somewhere, the ms3x is non inverting yes?
I want both wheels non inverting, and both setup to trigger rising edge in TS yes?

Also, while I'm pulling the ECU out, I need to check that the ms3x pullup is disabled.
RX7 Series 2 13B Turbo. Megasquirt 3 with 3X Expander and V3 CPU. Firmware 1.4.1
Knock module, twin EGT, real time clock, WBO2, full sequential fuel and spark
http://web.aanet.com.au/arran
arran
Master MS/Extra'er
 
Posts: 585
Joined: Mon Oct 29, 2012 2:34 am
Location: Brisbane Australia

Re: Sync loss 13B rotary

Postby muythaibxr » Mon May 09, 2016 5:19 pm

IIRC it is non inverting. You will probably have to mess with your tooth #1 angle if you are changing the primary trigger to non inverted.
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.

:msq:
muythaibxr
Site Admin
 
Posts: 8096
Joined: Thu Oct 14, 2004 12:48 pm

Re: Sync loss 13B rotary

Postby arran » Tue May 10, 2016 3:09 am

Confirmed, it is quite a rabbit warren revisiting the detail of the VR circuit setup! Examining the VR circuit diagrams for both the MS3 and the MS3X it is clear that I have MS3 VR inverted, and the MS3X not inverted (opposite actually, because it is the -ve (inverting) input that is the input to MS3 and MS3X U7A Op amps). I will keep the phasing of both the crank and cam VR sensors consistent

muythaibxr wrote:IIRC it is non inverting. You will probably have to mess with your tooth #1 angle if you are changing the primary trigger to non inverted.


MS3 - has the U7B Op amp daisy chained off the U7A producing a waveform 180 degrees out of phase.
ms3 VR circuit1.jpg


MS3X - the second Op amp is disconnected
ms3x VR circuit1.jpg
RX7 Series 2 13B Turbo. Megasquirt 3 with 3X Expander and V3 CPU. Firmware 1.4.1
Knock module, twin EGT, real time clock, WBO2, full sequential fuel and spark
http://web.aanet.com.au/arran
arran
Master MS/Extra'er
 
Posts: 585
Joined: Mon Oct 29, 2012 2:34 am
Location: Brisbane Australia

Re: Sync loss 13B rotary

Postby muythaibxr » Tue May 10, 2016 3:46 am

Wait you wired VR- on both to the input?
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.

:msq:
muythaibxr
Site Admin
 
Posts: 8096
Joined: Thu Oct 14, 2004 12:48 pm

Re: Sync loss 13B rotary

Postby arran » Tue May 10, 2016 5:02 am

No, I think you are asking if I wired the VR sensor -ve to the VR circuit inputs (rather than to sensor ground). I have not done that
RX7 Series 2 13B Turbo. Megasquirt 3 with 3X Expander and V3 CPU. Firmware 1.4.1
Knock module, twin EGT, real time clock, WBO2, full sequential fuel and spark
http://web.aanet.com.au/arran
arran
Master MS/Extra'er
 
Posts: 585
Joined: Mon Oct 29, 2012 2:34 am
Location: Brisbane Australia

Re: Sync loss 13B rotary

Postby arran » Fri May 13, 2016 8:58 pm

Still broken.

Changed the MS3 to omit U7B op amp, so TSel is now connected to VROut. Re-timed the engine (it retarded about 5 degrees).

Went for a gentle drive yesterday, and this morning with a bit more confidence in the change, I booted it for a brief trip to 8000 in 1st gear. Sync loss :(

Now I'll change the ground so the main ground point is the back of the engine block.
RX7 Series 2 13B Turbo. Megasquirt 3 with 3X Expander and V3 CPU. Firmware 1.4.1
Knock module, twin EGT, real time clock, WBO2, full sequential fuel and spark
http://web.aanet.com.au/arran
arran
Master MS/Extra'er
 
Posts: 585
Joined: Mon Oct 29, 2012 2:34 am
Location: Brisbane Australia

Re: Sync loss 13B rotary

Postby arran » Sat May 14, 2016 11:26 pm

Changed the main ground from the chassis to the block last night. Went for a run with the Mazda Car Club today, problem persists.
No sync loss at 7500 rev cut, sync loss at 8000 rev cut. Every time.
RX7 Series 2 13B Turbo. Megasquirt 3 with 3X Expander and V3 CPU. Firmware 1.4.1
Knock module, twin EGT, real time clock, WBO2, full sequential fuel and spark
http://web.aanet.com.au/arran
arran
Master MS/Extra'er
 
Posts: 585
Joined: Mon Oct 29, 2012 2:34 am
Location: Brisbane Australia

Re: Sync loss 13B rotary

Postby muythaibxr » Sun May 15, 2016 5:21 am

Can you get a composite log?
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.

:msq:
muythaibxr
Site Admin
 
Posts: 8096
Joined: Thu Oct 14, 2004 12:48 pm

Re: Sync loss 13B rotary

Postby arran » Sun May 15, 2016 5:50 pm

There is a composite log attached in the first post, and I will get another soon to see how it compares now that I've changed the Vout phase and the grounding.

The composite log in the first post shows the 2 tooth cam wheel trace with additional triggers after 4 crank pulses consistently. This appears at around 7300mSecs. There should only be a cam pulse for every 12 crank pulses.
RX7 Series 2 13B Turbo. Megasquirt 3 with 3X Expander and V3 CPU. Firmware 1.4.1
Knock module, twin EGT, real time clock, WBO2, full sequential fuel and spark
http://web.aanet.com.au/arran
arran
Master MS/Extra'er
 
Posts: 585
Joined: Mon Oct 29, 2012 2:34 am
Location: Brisbane Australia

Re: Sync loss 13B rotary

Postby muythaibxr » Sun May 15, 2016 6:34 pm

Yes sorry, but could you turn on the noise filters on both triggers and take composite logs? I want to see if you're getting crosstalk or similar, which could be resolved with my crosstalk filter, but it's easier to see if that's the case if you turn on the noise filter, which will cause both edges of both signals to be captured.

Ken
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.

:msq:
muythaibxr
Site Admin
 
Posts: 8096
Joined: Thu Oct 14, 2004 12:48 pm

Re: Sync loss 13B rotary

Postby arran » Sun May 15, 2016 6:40 pm

Will do
RX7 Series 2 13B Turbo. Megasquirt 3 with 3X Expander and V3 CPU. Firmware 1.4.1
Knock module, twin EGT, real time clock, WBO2, full sequential fuel and spark
http://web.aanet.com.au/arran
arran
Master MS/Extra'er
 
Posts: 585
Joined: Mon Oct 29, 2012 2:34 am
Location: Brisbane Australia

Re: Sync loss 13B rotary

Postby arran » Fri May 20, 2016 7:17 pm

Attached is a datalog corresponding composite log taken at the same time showing 8000rpm sync loss. Immediately prior to the log I was able to bounce off 7500 rev limit no problem. I'm entering an area here that at this time I don't know a lot about. The big gap which seems to be on both cam and crank is on log page 40 at 35800mSecs.

Mainloop time is included in this log. It shows time trundling along at 900uSecs, then jumps to 1118uSecs when 8000 rev cut is activated and the sync loss happens. I do not understand how to interpret this into CPU utilisation. Advice appreciated.

Noise filtering has been enabled which was an interesting experience. Because the earlier composite log showed sync loss on the cam signal (2 teeth wheel) I enabled the filtering on the cam pulses. The engine would not start with any combination of "Tach Period Rejection" or "Tach interrupt masking" setting, leaving the "Noise Filtering" off. I started out with 0.1 and 50% (50% because the initial composite log showed the error was 4 pulses into a 12 pulse cycle), 0.1 will not allow any smaller values, and I reduced the % through 40, 30, 10. No start. I disabled those two and enabled "Noise Filtering". Even though TS does not ask for a power cycle it appears to need one. I left the number at 416uSecs, and left the curve. Car started fine. It had a small miss shortly after I pulled away which does not normally happen, and aside from that ran normally. I took the below logs with the Noise Filtering as described above. I have arrived home and reverted to Noise Filtering off.

2016-05-21_11.26.15._composite 8000 syncloss.csv


2016-05-21_11.25.46.msl
RX7 Series 2 13B Turbo. Megasquirt 3 with 3X Expander and V3 CPU. Firmware 1.4.1
Knock module, twin EGT, real time clock, WBO2, full sequential fuel and spark
http://web.aanet.com.au/arran
arran
Master MS/Extra'er
 
Posts: 585
Joined: Mon Oct 29, 2012 2:34 am
Location: Brisbane Australia

PreviousNext

Return to MS3 General Support

Who is online

Users browsing this forum: No registered users and 2 guests