Nissan RB25 CAS, how can I help?

Testing and development of Megasquirt 3

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winstonusmc
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Re: Nissan RB25 CAS, how can I help?

Post by winstonusmc »

Added the pullup resistors, used 1k ohm. I can see the signal coming in on PT4 right now. Its not very stable and it loses sync sporadically and totally loses sync at 4000rpm. Here is the log file:
Test 1.msl
Nissan Skyline R34 RB26DETT ran MS3/MS3X w/ factory Hitachi CAS (sold)
Nissan Silvia S14 RB25DE ITB/NA ran MS3/MS3X w/ factory Mitsubishi CAS (disassembled)
Datsun 240z RB25DE ITB/NA with MS3/MS3X
winstonusmc
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Re: Nissan RB25 CAS, how can I help?

Post by winstonusmc »

I had a setting wrong I guess. I returned the "flip polarity on hi-res tach" to normal and now it keeps sync at 5000rpm as my drill is 2500rpm. Not really sure where the noise is coming from though.
Test 2.msl
Nissan Skyline R34 RB26DETT ran MS3/MS3X w/ factory Hitachi CAS (sold)
Nissan Silvia S14 RB25DE ITB/NA ran MS3/MS3X w/ factory Mitsubishi CAS (disassembled)
Datsun 240z RB25DE ITB/NA with MS3/MS3X
jsmcortina
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Re: Nissan RB25 CAS, how can I help?

Post by jsmcortina »

Have you taken composite logs ? They are more useful to getting a new wheel supported. Your datalogs do show that things are _close_ .

If I remember correctly from the work in the Optispark topic, we found that the "crank" input circuit is not fast enough and we had better results by bypassing it.
Technically what happens is that the capacitors in the circuit turn the nice square wave input signal into a sloppy rounded signal at higher rpms and this was then causing sync-loss as the tooth edge could not clearly be seen.

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

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winstonusmc
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Re: Nissan RB25 CAS, how can I help?

Post by winstonusmc »

So is the coding actually ready to try to plug it into an engine and attempt to run it? Or is there still work to be done?
Nissan Skyline R34 RB26DETT ran MS3/MS3X w/ factory Hitachi CAS (sold)
Nissan Silvia S14 RB25DE ITB/NA ran MS3/MS3X w/ factory Mitsubishi CAS (disassembled)
Datsun 240z RB25DE ITB/NA with MS3/MS3X
jsmcortina
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Re: Nissan RB25 CAS, how can I help?

Post by jsmcortina »

I'm waiting on testers (like you) to tell me!

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

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winstonusmc
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Re: Nissan RB25 CAS, how can I help?

Post by winstonusmc »

Rock solid to 10k. I figured the drill motor was causing a lot of noise for my un-shielded wiring so I figured something else. I used my road bicycle to turn the CAS and was able to see noise free logging to 10,000rpm before it loses sync. Not really sure why it loses sync, but it just drops for a second before it recovers. I couldnt log it for some reason though. This will give me what I need though. Please forgive the rough RPM line, I was cranking the pedal by hand. Later this week, I will try to hook it up to my RB26 in the R34. I wont be able to drive it good though as I am not sure how I am going to tackle the AWD system just yet.
test3.msl
test4.csv
Nissan Skyline R34 RB26DETT ran MS3/MS3X w/ factory Hitachi CAS (sold)
Nissan Silvia S14 RB25DE ITB/NA ran MS3/MS3X w/ factory Mitsubishi CAS (disassembled)
Datsun 240z RB25DE ITB/NA with MS3/MS3X
jsmcortina
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Re: Nissan RB25 CAS, how can I help?

Post by jsmcortina »

Before trying to drive it, you'll need to check the cranking timing and cylinder phasing. Ensure the injectors are disconnected and use your timing light. It is highly likely that this is wildly incorrect at the moment, but if you have solid sync, it is easy to remedy.

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

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
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winstonusmc
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Re: Nissan RB25 CAS, how can I help?

Post by winstonusmc »

Will I have to check the phasing of all cylinders or just the first one? I read the procedure for checking timing, is this what I use?
Nissan Skyline R34 RB26DETT ran MS3/MS3X w/ factory Hitachi CAS (sold)
Nissan Silvia S14 RB25DE ITB/NA ran MS3/MS3X w/ factory Mitsubishi CAS (disassembled)
Datsun 240z RB25DE ITB/NA with MS3/MS3X
jsmcortina
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Re: Nissan RB25 CAS, how can I help?

Post by jsmcortina »

Just the first one should be ok. The timing (and phasing) could be totally incorrect. So do check it and let me know what you find. If it is within a few degrees you can temporarily use the trigger offset/angle to adjust it. Larger changes need a code tweak.

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

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
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winstonusmc
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Re: Nissan RB25 CAS, how can I help?

Post by winstonusmc »

Patch harness is complete enough to test and run the engine. Tomorrow, I will test the phasing and attempt to start it. Have tested the patch harness already and made sure the AIT, engine temps, TPS, wideband, fuel pump, and it sees the cranking RPM as well. I was having an issue with the coil fuse blowing but could not tell why, so I upped the fuse size and it is fine. I hope all goes well.
Image
Image
Nissan Skyline R34 RB26DETT ran MS3/MS3X w/ factory Hitachi CAS (sold)
Nissan Silvia S14 RB25DE ITB/NA ran MS3/MS3X w/ factory Mitsubishi CAS (disassembled)
Datsun 240z RB25DE ITB/NA with MS3/MS3X
greeny510
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Re: Nissan RB25 CAS, how can I help?

Post by greeny510 »

Hi guys im new to megasquirt, ive just ordered a ms3x and im putting it on a tb48de, vtc which to me seems like a big block rb25, ill be wiring it in this weekend and will keep you posted. I would like to help with testing the 360 cas.
winstonusmc
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Re: Nissan RB25 CAS, how can I help?

Post by winstonusmc »

Got it running. I ended up with 98.5 degrees offset on the trigger angle. I cant get it to rev over 3600rpm before it loses sync. I may not be doing something right, but I am tired now. Here is my config and a datalog.
2011-11-10_15.19.18.msl
rb26.msq
2011-11-10_15.28.23.csv
Nissan Skyline R34 RB26DETT ran MS3/MS3X w/ factory Hitachi CAS (sold)
Nissan Silvia S14 RB25DE ITB/NA ran MS3/MS3X w/ factory Mitsubishi CAS (disassembled)
Datsun 240z RB25DE ITB/NA with MS3/MS3X
winstonusmc
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Re: Nissan RB25 CAS, how can I help?

Post by winstonusmc »

After reviewing my tune file, I noticed that the "ignition input capture" was set to falling edge. On the Optispark setup, it mentions it should be rising. Which is correct? I would assume its not my setting.

Also, when viewing the Tooth Logger, I noticed the level got down to .5(volts?) when it lost sync. Maybe a less Ohm pullup resistor might work, or I have read 12v used sometimes?
Nissan Skyline R34 RB26DETT ran MS3/MS3X w/ factory Hitachi CAS (sold)
Nissan Silvia S14 RB25DE ITB/NA ran MS3/MS3X w/ factory Mitsubishi CAS (disassembled)
Datsun 240z RB25DE ITB/NA with MS3/MS3X
winstonusmc
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Re: Nissan RB25 CAS, how can I help?

Post by winstonusmc »

Took another crack at the Megasquirt tonight. I had a 1k ohm resistor for the pullup on the high res side and thought that dropping the resistance would change things, it did not. It still loses sync almost in the exact same spot everytime. I am about to say screw it and get a lower res trigger wheel, but I want to see if anyone has any ideas? Things havent changed from the previous post. I obviously am going through PT4 for the high res. Could it be a setting or the temporary code?
Nissan Skyline R34 RB26DETT ran MS3/MS3X w/ factory Hitachi CAS (sold)
Nissan Silvia S14 RB25DE ITB/NA ran MS3/MS3X w/ factory Mitsubishi CAS (disassembled)
Datsun 240z RB25DE ITB/NA with MS3/MS3X
280GE 1JZ
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Re: Nissan RB25 CAS, how can I help?

Post by 280GE 1JZ »

James,

I still can't crack this RB25 trigger. But I managed to get crank reading today after previously only cam reading. I wired both pullup to 12v then readings on both cam and crank. I tied Optispark, RB25, log crank and cam. I also tried vrout-tsel, vroutinv-tsel, ignition input rising and falling, flip hi res polarity, and still no rpm. What is my mistake?

And also tried to change to alpha 16, previously 14. But then got warning about MAP accel enrichment and TPS accel enrichment.

Regards,
Doddy
280GE 1JZ
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Re: Nissan RB25 CAS, how can I help?

Post by 280GE 1JZ »

Cable from top to bottom:

CRANK - Lo Res
Cam -n Hi Res
12v
Ground
280GE 1JZ
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Re: Nissan RB25 CAS, how can I help?

Post by 280GE 1JZ »

Forgot to mention that I have to select 8 Cylinder for optispark and can't do VVt function. With RB25 setting also can't do vvt function. Can't use optispark for RB25 engine.

Regards,
Doddy
morrische
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Re: Nissan RB25 CAS, how can I help?

Post by morrische »

another person who want's to help. with the nissan (16,12,8,4/360).
So i have a ms3 v3.57 frimware 0225.010.

Settings logcrank&cam
High res on PT4 (360°) (MS3xcard db37 pin 32)
Low res on Tach (16,12,8,4) (jimstim)
2* Pullup 10k to 12V
In low rpm range you see the high res signal and no crank signal
in high rpm range (driven by drill) high res signal disappears and you just see the crank signal ?!?

with settings basic trigger and capture falling edge i have a nice stable rpm signal until 5000 rpm (2500 drill) perfect.

Is it possible that pt4 is to slow to see the 360° signal? (or the circuit on the ms3x card?!?)
I dont upload logs because they are useless in my opinion

Is it possible to program a jimstim with this wheelpattern?

My problem is i have no programming skills. :-(
Last edited by morrische on Sun Dec 04, 2011 7:23 am, edited 1 time in total.
jsmcortina
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Re: Nissan RB25 CAS, how can I help?

Post by jsmcortina »

280GE 1JZ wrote:Forgot to mention that I have to select 8 Cylinder for optispark and can't do VVt function.
The Optispark is only used on a V8 and doesn't have VVT, so that's as expected
With RB25 setting also can't do vvt function. Can't use optispark for RB25 engine.
Nissan CASes don't support fully variable VVT, so that's as expected.

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

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jsmcortina
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Re: Nissan RB25 CAS, how can I help?

Post by jsmcortina »

280GE 1JZ wrote:And also tried to change to alpha 16, previously 14. But then got warning about MAP accel enrichment and TPS accel enrichment.
I renamed two of the "indicators" to have shorter names that fitted in the boxes. Right-click on the dash and reload it.

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

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
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