the thread where Savington asks a lot of really, really dumb questions.
#21
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You may have already dealt with the issue, but you can use the MAF input (2O) as the input for your MAP. Althought the AEM does have the MAP input on plug 4, you can just go to the sensor setup and set the input to the MAF signal and it works. I found it much easier to use the MAF sensor wiring instead of running another signal wire.
#22
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You may have already dealt with the issue, but you can use the MAF input (2O) as the input for your MAP. Althought the AEM does have the MAP input on plug 4, you can just go to the sensor setup and set the input to the MAF signal and it works. I found it much easier to use the MAF sensor wiring instead of running another signal wire.
#30
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Oh snaps, it fired up. New MAP sensor fixed it. Swapped injectors as well so I set all that up again. Looks like I am seeing too many RPM, though - the engine sounds like it's lugging along at ~1000ish but RPM on the AEM says ~2000+.
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yeah, all my cam/crank sensor settings reset themselves. Set it all back and now RPM is half of what it should be. Car is giving little hints of firing but its not quite there.
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OK, got all the settings back to where they need to be as per Cuadra's 2001 VVT settings. It cranks and syncs but all I get are backfires. I have spark, I assume the backfires mean I have fuel, but I'm starting to wonder whether everything is firing in the right order. What datalog do you guys (Jason, Julien, et.al) need to help me diagnose this?
I'm so close...
I'm so close...
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When I first installed my COPs in sequential I had major backfiring. I played around until I got them to work. It wasn't until I reinstalled the OEM coils a month ago that I figured out what was wrong. The default AEM wiring/naming has "coil 1" being the wire that runs to the coil pack that fired cyls 2&3. "coil 2" fired 1 & 4.
This may not be your issue at all, and I run my COPs where coil 1 fires cyl 1, etc.
I was able to run the car on 1 or 2 cylinders while diagnosing the issue (activating one coil/injector at a time to see what cyls are backfiring). Definitely a scary time and sounds like rods are being bent. I blew my boost gauge hose off too.
This may not be your issue at all, and I run my COPs where coil 1 fires cyl 1, etc.
I was able to run the car on 1 or 2 cylinders while diagnosing the issue (activating one coil/injector at a time to see what cyls are backfiring). Definitely a scary time and sounds like rods are being bent. I blew my boost gauge hose off too.
#37
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The setup I posted requires that coil outputs 1,2,3,4 connect to COPs 1,2,3,4:
AEM trigger and dwell setup for '99~'05 with Toyota COPs - MX-5 Miata Forum
AEM trigger and dwell setup for '99~'05 with Toyota COPs - MX-5 Miata Forum
#38
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OK, got all the settings back to where they need to be as per Cuadra's 2001 VVT settings. It cranks and syncs but all I get are backfires. I have spark, I assume the backfires mean I have fuel, but I'm starting to wonder whether everything is firing in the right order. What datalog do you guys (Jason, Julien, et.al) need to help me diagnose this?
I'm so close...
I'm so close...
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#39
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Originally Posted by J_Man @ AEM Forums
Hi Savington,
I see that in your cam/crank setup you used the settings I did for '99/'00 Miata crank/cam pattern (I guess you got them from Jason). When synced with this pattern your sync point is 180 degrees shifted in the engine cycle -> '94 Miata stock syncs at cylinder #4 TDC and with the '99/'00 pattern and my sync pattern numbers the sync point is moved to cylinder #2 TDC.
Stat Sync'd (if that's what you mean by sync status) once switches to ON stays steady while cranking, right?
What about the Sync Errors param? How does that behave while cranking?
I see that in your cam/crank setup you used the settings I did for '99/'00 Miata crank/cam pattern (I guess you got them from Jason). When synced with this pattern your sync point is 180 degrees shifted in the engine cycle -> '94 Miata stock syncs at cylinder #4 TDC and with the '99/'00 pattern and my sync pattern numbers the sync point is moved to cylinder #2 TDC.
Stat Sync'd (if that's what you mean by sync status) once switches to ON stays steady while cranking, right?
What about the Sync Errors param? How does that behave while cranking?
Since you're using a 1710 EMS with a 2002 motor, I guess you did custom wiring and not exactly using a '94 OEM harness.
So, please can you check the four injection and two ignition pins (two because you said wasted spark) you're using on the 1710 EMS box to which injectors & coils you have those connected.
I want to know which is connected where so I can verify whether your ignition/injection phasing tables are correct.
So, a list of the 6 pins please
: AEM connector pin name -> where it is connected on the car which injector, or which coil.
IIRC Jason wired his car a bit different (he is using a Honda AEM EMS box in his Miata so he did his custom wiring) and he did the approriate changes in the software, so if you're copying blindly those, your ignition and injection might be out of phase big time which leads to lots of fuel smell and backfires.
So, please can you check the four injection and two ignition pins (two because you said wasted spark) you're using on the 1710 EMS box to which injectors & coils you have those connected.
I want to know which is connected where so I can verify whether your ignition/injection phasing tables are correct.
So, a list of the 6 pins please
![](https://www.miataturbo.net/images/smilies/smile.gif)
IIRC Jason wired his car a bit different (he is using a Honda AEM EMS box in his Miata so he did his custom wiring) and he did the approriate changes in the software, so if you're copying blindly those, your ignition and injection might be out of phase big time which leads to lots of fuel smell and backfires.
![wink](https://www.miataturbo.net/images/smilies/wink.gif)
The motor is a 2002, but I'm not using any of the 2002 wiring. Wiring is pretty much all 1994 stock, except for the cam and crank sensors which I built a harness to feed into the OEM CAS harness.
Injector wiring is stock 1994:
Injector 1 is 2U
Injector 2 is 2V
Injector 3 is 2Y
Injector 4 is 2Z
Coils are wired wasted spark through the '94 wiring:
Coil 1/4 is wired through 1G
Coil 2/3 is wired through 1H
I am not adverse to re-wiring the coils in sequential - if I did that, I'd follow the AEM pinout sheets, so:
Coil 1 to 1H
Coil 2 to 1G
Coil 3 to 3A
Coil 4 to 3B
Interesting to note that the AEM pinout says that 1G is for coil 2, and 1H is for coil 1 (opposite of what I have), but the 1994 wiring diagram puts coils 1/4 on 1G and coils 2/3 on 1H. Typo in their pinout?
OEM crank sensor signal is wired through 2E
OEM cam sensor signal is wired through 2G
If you can bear to explain it, I would love to hear how all of these settings relate to the motor. This is sort of a new area of the car for me - I have never been a big wiring/circuits/electronics guy.
P.S. You know me under a different nick name on other forums :-P
About the cranking rpm. Miatas crank at around 120 rpm. With perfectly charged battery I guess you might achieve 300 rpm. But no way you're cranking nowhere near 600 rpm.
About the cranking rpm. Miatas crank at around 120 rpm. With perfectly charged battery I guess you might achieve 300 rpm. But no way you're cranking nowhere near 600 rpm.
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Last edited by Savington; 02-12-2010 at 02:25 PM.
#40
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Let's say long time ago I know of a garage which was similar to yours ![Laugh](https://www.miataturbo.net/images/smilies/laugh.gif)
Not a typo. That's why I asked you about the info above, but looks like you're advancing fast by yourself too ![Stick Out Tongue](https://www.miataturbo.net/images/smilies/tongue.gif)
Someone at AEM just decided that in the Miata wiring the EMS output named "coil 2" should be wired to fire the 1/4 coil and the output named "coil 1" should be wired to fire the 2/4 coil.
So, if using the '94 AEM startup calibration as a base, but you wire the harness differently, you have to change the numbers in the software calibration to match your new wiring ('cause you'll have the spark by 180 degrees otherwise)
I'll look at your numbers in the calibration and will get back to you
![Laugh](https://www.miataturbo.net/images/smilies/laugh.gif)
![Stick Out Tongue](https://www.miataturbo.net/images/smilies/tongue.gif)
Someone at AEM just decided that in the Miata wiring the EMS output named "coil 2" should be wired to fire the 1/4 coil and the output named "coil 1" should be wired to fire the 2/4 coil.
So, if using the '94 AEM startup calibration as a base, but you wire the harness differently, you have to change the numbers in the software calibration to match your new wiring ('cause you'll have the spark by 180 degrees otherwise)
I'll look at your numbers in the calibration and will get back to you
Last edited by j_man; 02-12-2010 at 04:13 PM.