Help with building your Speeduino, installing it, getting it to run etc.
#49547
Hi fellas,
I have just installed a Core4 PNP ECU from DIY-EFI and it is giving me some issues when it comes to getting the car running.
All the hardware has been installed (TPS, Wideband Controller, MAP Vac Line) and the most recent firmware and base map loaded (202103 Firmware).
Initially, I had to jump the AFM connector and switch the fuel pump pin to A9 to get it to prime on the key, however it has suddenly stopped working, the pump no longer primes or runs. If I jump F/P and GRND in the diagnostic port, it works fine.
Also, it appears that the car has also lost spark as well as fuel pump, as it has gone from trying to start (coughing, farting, backfiring and sometimes running rough for around 5 seconds) to being dead in the water.
I am no expert when it comes to TunerStudio or Arduino/Speeduino, this is the first time I have attempted anything ECU related.
If anyone has any ideas or info on where to start/what to check, please let me know, as this has turned into a right head scratcher :?
#49787
Sorry for the long belated reply, work got in the way of things.

I have discovered that the ecu isn't outputing 12V to the fuel pump relay, even though all the pins are set right.
The only way I can get the fuel pump to come on is if I load the MX5 89-95 PnP base map from speedyloader, change the board to Core4 v1.0 and then set the fuel pump output pin to A9, then it will work, but changing anything within the map causes it to stop working again. Also seem to be randomly loosing spark.
The ST_SIG fuse is removed, and I have had the car randomly start at certain points but it runs like a dog and stalls out within 5 seconds.
Starting to think that there is something wrong with the ECU or the program, but I am no expert.
Also tried to upload the tune and map to this post but I just get an error whenever I attach the file.
Thanks. Jack
#49788
Lester371 wrote: Sat Apr 24, 2021 1:57 pmI have discovered that the ecu isn't outputing 12V to the fuel pump relay, even though all the pins are set right.
Basic info that will make your life easier ;)
PSIG wrote: Fri Aug 16, 2019 1:01 amThis is basic to using Speeduino or other EFI. All control outputs (injectors, fan, VVT, etc) are grounding, with the special exceptions of ignition and stepper IAC, which have switching positivegrounding output signals.

David
So, your relay should have +12V to the relay coil, then Speeduino grounds the coil to energize the relay.

Image
#49820
PSIG wrote: Sat Apr 24, 2021 2:39 pm
Lester371 wrote: Sat Apr 24, 2021 1:57 pmI have discovered that the ecu isn't outputing 12V to the fuel pump relay, even though all the pins are set right.
Basic info that will make your life easier ;)
PSIG wrote: Fri Aug 16, 2019 1:01 amThis is basic to using Speeduino or other EFI. All control outputs (injectors, fan, VVT, etc) are grounding, with the special exceptions of ignition and stepper IAC, which have switching positivegrounding output signals.

David
So, your relay should have +12V to the relay coil, then Speeduino grounds the coil to energize the relay.

Image
I thought that might be how it working, but the drawings that I have to hand for the fuel pump circuit suggest that the ECU gives the 12V signal to a secondary coil in the relay, instead of ST_SIG, but at least I know for sure now :)

Sod's law that I go out to the car to get a log to post, and the fuel pump works first time every time :oops:
I'm sure it will stop at some point like on many past attempts to start it. Still not even attempting to start, even with the same tune or a slightly altered base map. I can post the tune I am using, however I'm not sure how to post a log, as when I try to attach the .mgl file to this post, it tells me 'Invalid file extension: Log for Fuel Pump.mlg'.
It's likely me doing something wrong, so if anyone could shed some light, it would be much appreciated.

Thanks. Jack
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#49824
theonewithin wrote: Sun Apr 25, 2021 2:05 pm Speeduino outputs go to ground when active.

They do NOT supply 12v.

No idea what diagram you are looking at but it won't be for a Speeduino.
Yeah, the wiring diagrams are just for the car itself. I initially thought it could be a dodgy connection or a fault with the wiring. This led me to believe that the Violet wire from the ECU to the fuel pump relay was what the Speeduino used to supply 12V to bring it in, since the Black wire is just ground, so I assumed it was 12V+ because otherwise the ECU would just be grounding a ground :? Obviously I've either got crappy diagrams or the ECU utilises this wiring differently.
#49938
UPDATE:

Car is now running and I am in the process of tuning the map.
Ended up getting in contact with DIY-EFI and they sent me a different map for the Core4 ECU. Turns out they use Pin 36 for the fuel pump, which doesn't require a jump lead in the old AFM connector.
Injector layout was also changed to semi-sequential, but the one thing that actually got the car running was turning off 'Multiply VE value by MAP ratio' on the VE Table.
This has turned out to be a steep learning curve for me, thanks for all the help! :)

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