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NB1 - Starts and stalls after seconds

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Old 01-19-2020 | 06:40 PM
  #1  
vtbandit's Avatar
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From: Dacula, GA
Default NB1 - Starts and stalls after seconds

Setup:
- USDM 1999 miata
- MS3 mini ecu
- stock engine except for squaretop IM, K&N typhoon intake, and racing beat header.
- stock IAT and coolant sensors
- New AEM x-series 30-0300. 12v switched power from radio fuse. power ground is at throttle body and shares the same bolt as the the ECU harness ground. signal and signal ground are connected to OEM loom O2 sensor plug (how it is designed with the MS3 mini)

Observations & issues:
- Car will only idle for ~2-3 seconds and will then stall
- After turning the ignition to ON, Tunerstudio takes approximately 20 seconds to read the wideband signal (for the first 20 seconds it is at 7.8 AFR). Reading the AEM gauge, the gauge only needs ~5 seconds to show AFR.
- The car takes a while to start (~5 seconds), will only go up to about 700 rpm. while that is happening the ecu is seeing 7.8 from the WBO2 but the gauge is showing 15ish. The car then slowly reduces fuel and then it stalls.

What I've done so far:
- I've been watching several @Pedxing youtube videos that are stickied
- tested various setups and settings between the initial basemap from Rev and with Pedxing showed in the videos

Setup & datalogs are attached

Any input or suggestions are appreciated.

Thanks!
Attached Files
File Type: msq
CurrentTune.msq (274.4 KB, 48 views)
File Type: msl
2020-01-19_16.33.09.msl (200.3 KB, 70 views)
Old 01-19-2020 | 08:38 PM
  #2  
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Your Minimum idle valve duty is too low. Raise to at least 28 and work your way from there. Also no reason for max duty to be at 70 (set it to your highest cranking duty).
Play with your crank duty. Seems too low to me. Mine is at 50. This will get the revs up after cranking.
Old 01-19-2020 | 09:47 PM
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From: Commiefornia
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Is your afr really 7:1. Turn off the fixed advance and add in some extra advance in the cold advance table below 80degrees. Duty will depend on how your air bypass is adjusted. I usually set the bypass to 100rpm below the min duty.
Old 01-23-2020 | 10:29 AM
  #4  
vtbandit's Avatar
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Quick update:
Thanks for the help. I spent ~4 hours that last few evenings trying the suggestions above without success. I was reviewing some MSPNP install instructions over lunch yesterday and realized that the MS3 has a jumper for the fuel pump (with and without immobilizer). I haven't opened up the ECU, but I referenced a picture I took prior to install and the jumper looks like it was set for a EUDM miata with immobilizer. I'm going to change it this evening and hope for the best.

Picture of jumper:

Old 01-23-2020 | 09:04 PM
  #5  
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My gut, and your O2 sensor, says you are lean. I would start with increasing VE in the 500 RPM column equal to the 700. Then I would add enough VE in the 50kPa range to get your running, just started AFR to around 11 to 12. I don't think the lean is only ASE and WUE. I think it is basic VE. But you could also experiment with the ASE and ASE taper to give more fuel to run longer, if you would prefer that approach.

I am presuming that you have not gotten the car to run sufficiently to complete setting your timing.

Also, I would set incorporate AFR in the General Settings. Not that this has anything to do with your issue, but it needs to be done before you start tuning, in case you someday wish to change your AFR table without having to also change the VE table.

Can you not hear if your pump stops running? 1999 has no immobilizer. Also, if your pump stopped, your die would be virtually instantaneous, not the slow death your log shows.

DNM
Old 01-23-2020 | 09:23 PM
  #6  
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Originally Posted by DNMakinson
A lot of super useful input... DNM
Thanks for the inputs. I'm making some changes now based on your input.

It ended up being the jumper. Car started up on first attempt. Now I'm taking my pages of notes from reading MT threads and manuals and start getting this thing running!!!
Old 01-24-2020 | 08:09 PM
  #7  
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I just saw this thread. I'm glad you got it running. Now the tuning begins.
Old 01-24-2020 | 10:35 PM
  #8  
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Originally Posted by sixshooter
I just saw this thread. I'm glad you got it running. Now the tuning begins.
thanks. The goal is to have it ready for track events in April and I’m making the trek up to Road Atlanta in June.
Old 01-26-2020 | 08:51 AM
  #9  
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I took a look and you still have Fixed Advance set. See the attachment. Have you set your timing?
That is some of my Ignition Pulldown menu on the left compared to yours on the right. I see that I have "Ignition Input Capture" as "Falling Edge" and you have "Rising Edge". I would love a coherent explanation from someone Miata saavy on which is correct.
You also have "Batch Fire During Crank" ON. I have it OFF. Not saying you're wrong, just sayin'.
You've got "Launch Control" ON. If you're really using it, fine, but I seem to remember it causing problems when it's left ON by default when you're not using it.

Old 01-26-2020 | 11:32 AM
  #10  
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Thanks for the response @poormxdad . I got the car up and running after I switched the fuel pump jumper. I need to go back and look at these configurations. No clue why I had launch control on.
Old 01-26-2020 | 12:52 PM
  #11  
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The manual isn't exactly definitive. That's a setting that can change according to the type of VR signal conditioner used but I would expect all MS3's to use the same type of conditioner.

On a different vehicle platform that uses the same type of VR sensor I've seen timing shift 6+ degrees with incorrect settings. I've you want to be sure your settings are right for your application just put a timing light on and watch for timing to shift as you increases RPM.




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