MRE LS1 Output Problems

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the_cheat
Posts: 2
Joined: Tue May 16, 2023 5:40 pm

MRE LS1 Output Problems

Post by the_cheat »

Hi,

Been working diligently for a few days to get a MRE 0.4.8 I bought in 2020 and never did anything with working on my NB1 Miata with VVT swap. Using a 76 pin adapter board labeled rusefi 0.2 or something like that I bought at the same time to connect it to the stock harness, plus an extra connector for stuff like VVT, WBO2 and MAP.

I have it running smoothly now in general and driving at least as well as the stock ECU other than startup (will post about it elsewhere to not clutter my specific question thread) but struggling with VVT control on the LS1 pin 7 output. I just jumped the wires from the IACV plug (working) to the VVT solenoid and changed the output in Tunerstudio from 7 to 3 to steal the IACV line and have working VVT now. I'm going to run it like that for the moment but eventually would like IACV back.

Initially, I didn't have the D15/d20 diodes in for a couple days of testing... Rookie mistake, I am new to all this. I soldered them in just now but still no input. Checked all wires from engine connectors back to ECU and everything is correct, both solenoid plugs get 12v on one pin and everything reads as it should with a multimeter, 0 ohms from each of the low side wire at the engine back to ECU connector 3 and 7.


Did I maybe damage the TLE8888 chip running it without the solenoid? I was reading the TLE8888 manual and this is all very new to me (I am a mech. engineer way out of my wheelhouse but doing my best) and it looks like it has pretty robust protections on those lines, it can fault out and turn the output off. It looks possible to read and then try turning that output back on from the TLE8888 chip using the RST/MON pins but they don't appear to be connected to anything on the MRE board.

Is there a way to bench test/get a visual or audible signal out of the LS2 line? In the Rusefi console software I can bench test the IACV successfully, and obviously there is the handy LS2 LED to look at as well. Is the TCU solenoid test supposed to control the LS1? I get a "no diag on this pin" message when I try it. Other stuff works when I bench test it.

Youtube video of testing VVT off the IACV input and a few pictures attached. Can share anything else if needed.





Thanks for any and all help! It's been an undertaking for me but I am very happy with my little $200 ECU project now that it is finally running the car :) just need to sort this out and do more tuning. Big thanks to the developers for all the work!
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AndreyB
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Re: MRE LS1 Output Problems

Post by AndreyB »

Can you temporary hack an injector on LS1? maybe even outside of car? and see if you click injector using LS1 while having a test config?
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the_cheat
Posts: 2
Joined: Tue May 16, 2023 5:40 pm

Re: MRE LS1 Output Problems

Post by the_cheat »

It is the simple embarrassing answer- I messed up the wiring despite my assurances I hadn't :oops:

I had the VVT feed off the low side of the IACV solenoid not high. Rewired VVT on its own 12v and all is OK now :)

Have work to do on VVT PID and table tuning but it works! It is noticeable. Very happy, VVT was the main reason I am finally doing this ecu (in NY my '99 car is done with it's last OBD2 inspection so I can run a standalone from here on out).

Car is doing it's first track weekend on the ECU this weekend, driving down to NJMP. Lots of tuning work to do but I have it running safe and smooth on AFR/timing and will be improving it with the help of an experienced friend through the weekend, dyno eventually.

I will post a "build thread" thing when I have the time but I'm happy it's all running properly now.


While I have your attention- I'd really like SD card logging so I can log on track without a laptop in the car. Can I use my J4 header on my 0.4.8 board in as described in the the link below for the NB2 PNP adapter board to connect to a SD breakout board or does that require firmware/etc. changes too?


https://wiki.rusefi.com/MREAdapter72/

Thanks!
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AndreyB
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Re: MRE LS1 Output Problems

Post by AndreyB »

the_cheat wrote:
Wed May 17, 2023 4:15 am
Can I use my J4 header on my 0.4.8 board in as described in the the link below for the NB2 PNP adapter board to connect to a SD breakout board or does that require firmware/etc. changes too?
there is a 50% change that SD card pinout has changed between 0.4.8 when it was a hack and 0.6.0 where it's properly on-board. Please compare schematics.
Very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions

Always looking for C/C++/Java/PHP developers! Please help us see https://rusefi.com/s/howtocontribute
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