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-   -   Car suddenly stops while accelerating (https://www.miataturbo.net/megasquirt-18/car-suddenly-stops-while-accelerating-108639/)

Nyirike 10-09-2023 03:37 AM

Car suddenly stops while accelerating
 
Hi

I built a track car from a MX NB 1.8 Turbo with MS3 Extra. It worked fine until yesterday afternoon. It stopped while I started accelerating from a turn and I couldn't start it again. I pulled over from the track and checked the dashboard (I use piDash) and it looked okay. 10 seconds of cranking the car started again and I could go back to the pit. Its weird because it used to start after 3-4 turns. Btw. I checked the engine bay and I didn't notice anything. I started again and kept it on idle for 10 minutes. Everyhting worked well. I went back to the track again but after the car reach the 5000 rpm the it stalled again several times (like a boost cut) and immediatelly started. So my track day was over. Luckily my ECU starts logging after 1200rpm so I have log . Before it started acting weird the battery charging drops to 12V. Maybe alternator issue? There is no sync loss in the log.

Any thoughts, idea, anything?

Thanks in advance. (Sorry for my English, it's not my native language)

Log: https://drive.google.com/file/d/1duJ...JKfx9v91_Gid0E

Godless Commie 10-11-2023 04:49 PM

What coils are you running?
I had similar problems with a Toyota COP setup and NGK copper plugs.
Switched over to red R8 coils and iridium plugs per Reverant's advice and all's good now.

natewin 10-12-2023 08:23 AM

Can you post tune as well? NB alt may be set to stop charging at WOT, 12v might be fine to keep coils going. You can set the tune to keep alt charging at WOT.

curly 10-15-2023 05:42 PM

If you have AFR safety enabled, that may be cutting ignition, since you're well above your target in most of that log. That's a stab in the dark without a tune though. With a track car, you should have a fuel pressure sensor wired to the ECU, and log it as well.

Nyirike 10-19-2023 05:14 AM

Thanks for everybody:
Godless Commie : I have Toyota COP and NGK plugs. I've been using these for years without any issue. :/

natewin: Good idea. I'll check the tune.

curly: The AFR was too lean because the Deadtime/Voltage correction was wrong. It became lean because the alternator stopped charging and ECU didn't drive the injector well. I fixed it, it's working as expected since then.

I tested and it looks like the ECU restarts somehow during acceleration. I talked with an electrical engineer who repairs car's ECUs and knows the MS3 well and he thinks that the ECU restarts beacause some interference occured on the ECU voltage feed and the processor restarted itself. So we put a condenser and a supressor for the ECU voltage feed lines. Btw this issue appeared after I installed the KPower Power Steering kit. It needs lots of power and it has massive power cables and its controller is close to the MS3. Maybe newly installed the supressor and condenser for the ECU will solve the issue.

This weekend I will got to a track to test it. We'll see...

natewin 10-19-2023 07:54 AM

I have an electric column on my 95 NA, ECU is behind pass seat. MS3PNP
Involved with a Champcar that has electric column, 99 NB, ECU above it just under windshield directly above column. MS3PNP
Friend also has an electric column in his 96 NA with Haltech ECU about 1-2 ft to the right of the column on the rollbar.

Mine is the one sold on eBay from ePowerSteering.com. The other two are DIY Saturn Vue columns with components needed to finish from ePowerSteering.com

Just some electric column data points.

rabid 10-22-2023 11:32 PM

I had this happen. It first started when I accelerated up a hill. After looking at the logs, I though for sure it was the boost solenoid going bad or something so I disconnected that. It got to the point that even a slow acceleration was enough. I thought it was a loose ground or power wire so I really went looking. It was the battery positive shorting on the hold down!


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