Speeduino - Open Source, Low Cost ECU stuff

Been a while since I've been able to play with my accord, due to a VW diesel truck coming into my life, but I've made a bunch of progress on my rebuild of my poor hatch over the last few weeks.

One of these things has been swapping in the wiring and bits from an LXI and installing a Speeduino ECU.

I thought it would be helpful to create a post here to share tip/tricks/advice on converting our cars to a bit more modern EFI cheaply.

My car:
1986 Accord CA5 Hatchback (DX)
Transmission 5 speed (E2Q5)
Engine A18A from JDM Accord (single downdraft carb)
Intake manifold USDM 87 accord LXi A20A3
Ignition coil: VW Golf 2.0L (2000) (still working on find coil side boots & plugs to make plug wires to support this....)
ECU: Speeduino UA4C (Fish Dog) ECU w/ a pigtail from SpeedyEFI. Hard spliced in but maybe official speeduino v0.4 and DCWerx's SS-OBD1 and a jumper harness (OBD0 to OBD1) maybe will make more sense for you...
MAP sensor: GM 1 bar
Harness: USDM 1987 LXi sedan (also where many parts have come from)
Distributor:
My a20a3 had smashed dizzy from carelessness pulling the donor engine :(
Like good hacker, I made one from many... I plan to remove cap & button and make a flush lid..
Don't do that.. It is waste of time.. Use A20A3 distributor and a VERY tiny bit of RTV. Only one bolt will hold it but it is OK.. You ONLY need the VR sensors in the bottom.
ECU Options: HC-06 Bluetooth, DSC (You should use Mini Max A2) VR conditioner, DRV8825 stepper driver

Anyways, I'll post next some useful diagrams and photos for those who might want to do this also.. Bear with me as I try to make it useful!

UA4C ECU Pinouts
Attachment 9667
Attachment 9668

There's also the option of using SS-OBD1 adaptor and a jumper (OBD0 to OBD1) with the official Speeduino v0.4 - Not a bad option, if you want almost 100% plug and play.

Stock Honda Wiring Diagram
Attachment 9674

Engine Setup
Ignition
You MUST NOT try to drive the OEM coil with these board as they do not have ignitor integrated...

VW single coilpack - Waste Spark
It is my choice of VW ignition coil from 2000 VW Golf 2.0L petrol, such as this one from amazon at ~20$ USD.
Attachment 9669

They contain TWO coils molded into one package with a replacable ignitor module. It's easily available in many parts stores.

Here is how to connect this coil:
Attachment 9670

TRIGGERS

Stock Distributor (OBD0) TDC and CYL pickups
These are VR type NOT hall sensors. This means they can produce a relatively high (90V) output when engine is running at high RPMs. You MUST NOT connect them directly to your board UNLESS you have a VR signal conditioner such as DSC or Mini Max A2 board (or do the hack below, in which case set jumpers for HALL type sensor and follow the hack instructions). You really do want the two channel as you will use the dual wheel decoder in that case to allow timing control (and sequential fuel / semi-sequential spark)

You could try a circuit like this to make it work --
Attachment 9673

Use the TDC output from stock dizzy as the "Dist R term" in the schematic - it's the VR signal you want. (4 tooth wheel)
You won't be able to run sequential UNLESS you use two GM modules (one for TDC and one for CYL)... but it still a start.. Seriously do the waste spark setup...

Attachment 9676

-- If you cannot convert to waste spark coils --
You could get by with fuel only perhaps by using stock coil with a GM HEI module as an ignitor, but it isn't ideal compared to the waste spark setup..

The module will function as your ignitor, protecting the low current output of the board from damage.

You will just hook up the coil to the GM HEI module as it is normally wired for a chevy 350 small block. the 4 (rather than 8) teeth on our wheel will make it work.

I'll try to edit these post and clean them up more soon!

[Blank Post 1 for ECU Configuration Guide]

[Blank Post 2 for Misc stuff]

I still am searching for a source of these style (VW) ignition coil side plugs & boots... Any ideas where to find???
It would be fitting a 99-00 VW Golf 2.0L for sure... See above coil image.
Attachment 9672

Someone's been busy. Nice work.

For the plug wires, why don't you try one of those universal cut to length kits like: https://shop.advanceautoparts.com/p/...40b/89012615-p

https://shop.advanceautoparts.com/wc...b_pri_larg.jpg


If you want another distributor mount bolt, grab the cam bearing cap with the dizzie mount stud from an LX-i. It will swap out easily.

Cool. I found I can actually fit 2 bolts with the a18a head as is. Got all the exterior back together besides bumper lights which I left elsewhere but will pick up in the next few days. I plan to use the make my own route but haven't been sure of what plug end for the coil side.https://uploads.tapatalk-cdn.com/201...fee339b5bb.jpg

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Quote:

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Originally Posted by fr0ggie

I found I can actually fit 2 bolts with the a18a head as is.

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Or there's that. LOL

Tons of info, this is awesome!

Oi. sorry for lack of progress. Blew up the diesel in my daily...https://uploads.tapatalk-cdn.com/201...243c41c330.jpghttps://uploads.tapatalk-cdn.com/201...01de139c38.jpghttps://uploads.tapatalk-cdn.com/201...65209cffb6.jpghttps://uploads.tapatalk-cdn.com/201...d437b93e76.jpghttps://uploads.tapatalk-cdn.com/201...eb80d520ca.jpghttps://uploads.tapatalk-cdn.com/201...6208cccc49.jpghttps://uploads.tapatalk-cdn.com/201...5096c8516b.jpghttps://uploads.tapatalk-cdn.com/201...0cd27dd2b3.jpg

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Hi....In terms of the voltage drop out, do you know what it was? I know there's a big battery voltage drop during cranking, so if the arduino is powered from a battery source, that could be a problem. So I wonder if the USB power system could be used since it can filter out the voltage drops better.
As for the crank signal- when I read the wiki last night, I noticed that it really wanted a hall effect sensor, and it didn't seem to have a decent VR signal solution. How did you end up solving that?

https://www.7pcb.com/