Nissan CAS Calibration Fix

[JP]

We finally got a NISSAN CAS that reported sync problems (thanks Sean Morris).

For those having a syncing problem...
The Fix:
Turn OFF Crank Falling Edge
Turn ON Crank Rising Edge

Today we tested the following Cam Angle Sensors back-2-back on our bench to see what the difference was. Both sensors have the same signals but are different in mechanical design (see attached).

NISSAN CAS made by Mitsubishi:
Sync'd everytime with the new and old calibration settings

NISSAN CAS made by Hitachi:
This CAS would sync on the bench, however, the S Tooth would switch values at 400RPM. Oddly enough, the vehicle swapped with another Hitachi CAS and worked fine(?)

As expected from previous tests (see attached), the falling edges seemed like a better choice to use than the rising edges (base map uses falling edge). However, we found that the use of the falling edge on the crank was causing the EMS to see different S Tooth values from the Hitachi CAS.

After finding this, we tested all of the other Nissan CAS (4 cyl included) and found that they can also use the Rising Edge of the Crank rather than the Falling edge.

For the latest Wizard File with these CAS changes go here:
http://forum.aempower.com/forum/index.php?topic=9156.0

[Lobster]

If I mod my CAS so the rising edge is like the falling edge, would that increase the reliability and accuracy of the CAS?

[krayton]

lil wierd FYI.

my rb25ems ran fine before.  never had any cas issues before.  ended up rebuilding and loading up the new 1.19 base map and u guys have the "fix" done.  my car wouldnt start when hot, but now that i switched it back to like it was before, it works fine. 


....dont really know what that means, but thought id share.

[tyndago7]

There is one CAS that a customer had modified.  The stock 360 slot thin wheels, seem to waver a bit at high RPMS.

http://picasaweb.google.com/tyndago/Skyline/photo#5049763310745891346

http://picasaweb.google.com/tyndago/Skyline/photo#5049763332220727842

[Full Race Geoff]

hmmm i gotta try one of those

http://forum.aempower.com/forum/index.php?action=dlattach;topic=20346.0;id=3851

There is one CAS that a customer had modified.  The stock 360 slot thin wheels, seem to waver a bit at high RPMS.

http://picasaweb.google.com/tyndago/Skyline/photo#5049763310745891346

http://picasaweb.google.com/tyndago/Skyline/photo#5049763332220727842

[vprtech]

Deleted.

[RSturbo]

I had a problem with the CAS. (95 R33 GTR)  It would run great for about 30 min and if it dropped below 2k rpm it would lope around 1krpm and never recover untill it sat for about a few hours. When I data logged some parameters to find out the problem was in the CAS, I swapped the CAS with another one I had in the shop and problem went away.  this is good to know,  this means I can redo some of the settings and get the old one to work again?  I polished it because I use the car for shows and figured that's why it went bad...

[RB25]

We finally got a NISSAN CAS that reported sync problems (thanks Sean Morris).

For those having a syncing problem...
The Fix:
Turn OFF Crank Falling Edge
Turn ON Crank Rising Edge

there is another one parameter is changed in U setup - the PICKUP DELAY COMP in the IGNITION PHASING menu - in U version it is 100 - in old version it is 0
may be any one else is changed?

[radianation]

lil wierd FYI.

my rb25ems ran fine before.  never had any cas issues before.  ended up rebuilding and loading up the new 1.19 base map and u guys have the "fix" done.  my car wouldnt start when hot, but now that i switched it back to like it was before, it works fine. 


....dont really know what that means, but thought id share.

I've got this problem. The car won't start when it's hot. A little starter fluid in the manifold and it fires right up though. I have the Hitachi CAS and had to run the calibration fix. Any ideas?

[Malkinator]

I am have just installed the EMS in my R32 GT-R. It is replacing an HKS F-Con Pro. The car has been running fine with the exception that I had to dial back the initial timing advance to prevent too much overall timing and that the fuel is a bit too rich in a few spots but not far off. Thus far I haven't been able to start the car with the AEM EMS. I thinkI've read pretty much all of the posts but am still not clear. Does one absolutely have to replace the factory CAS with an AEM CAS to make the thing work? Or should changing the thing from rising edge to falling edge be enough to make the stock CAS work with the EMS? I am using the calibration file provided by AEM for a MAP based RB26. I also tried the MAF based calibration since the MAFs are still connected as well. I have cranked it over and checked the timing with a timing light while the injectors were disabled. The timing looks correct to me, but I am having a hard time telling because of the relatively low cranking RPM and because once in a while the timing marks show up as being what I would say are retarded. The software did say SYNCED. However once I enabled the injectors and tried to start it, it no longer SYNCED. I did get a couple coughs but nothing too promising. I have been told that my blue top injectors are likely 680cc HKS injectors. I have selected 650cc/min 2ohm injectors from the menu. Is there anywhere that one can manually enter the injector size or make a global adjustment to the fuel map? I have tried cranking the motor at 10 degrees and 20 degrees with no perceivable difference. I also tried it configured for 440cc injectors with no difference. I did forget to go and check if the CAS was set to falling edge. Does anyone know if the AEM calibration comes with that set correctly now? Also what does Initialise ECU actually mean? I am using version 1.19. I saw that there was a 1.23 or something but that there were no calibrations that match that. I'm not exactly sure what that means. Also, how do I check the firmware version in the EMS. I looked through all the menus but could not find it. Anyways, an answer on if I absolutely need to replace the CAS would be a starter and any other advice is welcome. Could someone also please clarify the difference in the discs. Does the stock disk have 360 slots with 6 spark teeth trigger locations? Does the AEM disk have higher or lower resolution? I see that it has 24 teeth and that one needs to change the settings from 6 spark teeth to 24. So that indicates an increase in resolution to me. But the pictures that show the stock CAS as having very high resolution slots (360 presumably) indicates to me that it's a decreased resolution. How does the AEM use the 3 inside slots and why do they appear to be at about 90 degrees from one another? Also, my calibration shows that 3 coils are enabled? Why isn't it 6 coils? Does it fire the coils in the same manner as a stock ecu or does one essentially end up with a wasted spark kind of setup despite having 6 dedicated coils? Thanks in advance. I really hope someone has the tid bit of info I'm missing that will allow me to at least get it started.

[Malkinator]

I should also mention that my R32 GT-R has an R33 RB26 GT-R motor in it. Does that mean that the CAS is different and is there actually a different calibration file that I should be using?

[krayton]

lil wierd FYI.

my rb25ems ran fine before.  never had any cas issues before.  ended up rebuilding and loading up the new 1.19 base map and u guys have the "fix" done.  my car wouldnt start when hot, but now that i switched it back to like it was before, it works fine. 


....dont really know what that means, but thought id share.

I've got this problem. The car won't start when it's hot. A little starter fluid in the manifold and it fires right up though. I have the Hitachi CAS and had to run the calibration fix. Any ideas?

dang, never check this board anymore.  but yeah, the syncs on the settings need to be switched.  cant remember cause im not at home with the program.  PM if u get this and still need help