[Jonikopsuka]

I recently found out about this whole Speeduino business and the more I hear the more appealing it sounds to me.

I’ve got a 1984 Volvo 242 Coupe and this would be one of the possibilities for that car with the other being dual 45mm Weber carbs.

So now to the question at hand. The Volvo redblock I got handles ignition via distributor and has a vacuum actuated ignition advance for higher rpms.
Can I run the Speeduino system for just the fuel side and keep the ignition as is? It’d keep the whole lot a lot simpler and mainly cheaper on my side.

I imagine I could but it’d be nice to have concrete info before committing.

As for the fuel and intake side I got a spare set of Subaru injectors and fuel rails from an N/A EJ20, injectors from a Volvo 5 cylinder as well as a throttlebody with a TPS from the same 5 cylinder which I would need to check if it would work.

All that would leave is crank wheel and sensor and checking if the mechanical fuel pump can feed enough juice which I imagine it should since our old school Volvo guys have ran dual webers with the stock fuel pump.

Info regarding the ignition would be appreciated and I’m open to suggestions and improvements as well so if you got something then shoot.

[PSIG]

The Volvo redblock I got handles ignition via distributor and has a vacuum actuated ignition advance for higher rpms. Can I run the Speeduino system for just the fuel side and keep the ignition as is? It’d keep the whole lot a lot simpler and mainly cheaper on my side.

Fuel-only = OK. However, controlling ignition is often a first step, followed by fuel control. This is because ignition is as important as fuel in enabling maximum efficiency (power, economy, etc). Fuel guides the best timing, and timing allows the best fuel. They work and adjust together. It is just as 'simple' in concept to use Speeduino for ignition control as to leave it fuel-only, and provides substantial benefits. Consider both options.

As for the fuel and intake side I got a spare set of Subaru injectors and fuel rails from an N/A EJ20, injectors from a Volvo 5 cylinder …
All that would leave is crank wheel and sensor and checking if the mechanical fuel pump can feed enough juice …

Either way, you will have to tap the 'crank' signal for operation, and the difference is whether the distributor or Speeduino controls the coil firing.

Verify your injector specifications against your fuel pump spec's, as most Webers use low-pressure, while most injectors use high-pressure fuel. Read the Wiki sections that apply to your conversion lightly several times. Not too intensely. It will make more sense each time.

[Jonikopsuka]

I do recognise the advantages that come with ECU controlled ignition, especially since the timing on the Volvo can only be correct or 180 degrees incorrect, so in other words, no adjustability apart from the vacuum actuator.

The main thing is just that it would bring a sizeable amount of cost having to source the parts for it unless I could make some 2 and a half decade old Subaru ignition junk coils work with this system.
After that setting up all the ignition timing would take some work and considering that currently it’s already set and that I’m not trying to make this a hypermiler (not that I could with the aerodynamics of a brick) I just don’t see the worth in the extra work.

[PSIG]

Do as you see best, but I wasn't suggesting an ignition change—only a control change. Typically, this entails locking the distributor advance and routing the coil output pin to Speeduino, and Speeduino output pin to control the coil driver and coil. This is (again typically) a 2-wire change and adding a coil driver (as here in the Wiki). Very little cost to change control. Yes, you could also convert to coil packs or other system if you wanted to go further, but I wasn't suggesting that.

To be clear, the ignition timing is set in the original distributor, and those settings are for the original tune and factory purposes. Your purposes are likely different, and will need different timing settings to perform properly or best, whether power, economy, general driving response or engine life. These choices are yours, but you leave a lot of opportunity on the table when you ignore either fuel tuning or ignition tuning, because of how they work together. It is definitely worth it. It is your project, so do what you like, when you like. Have fun!

[Jonikopsuka]

It might be the language barrier but I fail to see how letting the ECU somehow control an old style fist sized ignition coil that takes its power straight from the alternator/battery would be in any way beneficial, especially considering that the distributor would still be doing all the timing work.

Also if you happen to have a recommendation to which version of the kit I should purchase and from where (pref. inside EU for less taxes) I’d appreciate that. There seem to be a lot of different versions and it gets a little confusing.

All in all this would be a good 2-300€ cheaper in total than the cheapest microsquirt and let’s not even talk about price jump going to MaxxECU

[PSIG]

It might be the language barrier but I fail to see how letting the ECU somehow control an old style fist sized ignition coil that takes its power straight from the alternator/battery would be in any way beneficial, especially considering that the distributor would still be doing all the timing work.

Yes, perhaps a language barrier, and you do not have to consider this now. The distributor is doing the spark timing now. With change in control to the ECM, the distributor does no timing work. The ECM does. The distributor then only signals the ECM the relative crankshaft position, and its work is done. Spark timing control (and its benefits) is now from the ECM. The coil and power source are irrelevant to the control of when it sparks.

Get your fuel working, and when tuning you will begin to see how control of the spark timing can allow much more freedom and effectiveness in how you use fuel. When you get to that point, we can talk about ignition options.

[runesm]

It might be the language barrier but I fail to see how letting the ECU somehow control an old style fist sized ignition coil that takes its power straight from the alternator/battery would be in any way beneficial, especially considering that the distributor would still be doing all the timing work.

Yes, perhaps a language barrier, and you do not have to consider this now. The distributor is doing the spark timing now. With change in control to the ECM, the distributor does no timing work. The ECM does. The distributor then only signals the ECM the relative crankshaft position, and its work is done. Spark timing control (and its benefits) is now from the ECM. The coil and power source are irrelevant to the control of when it sparks.

Get your fuel working, and when tuning you will begin to see how control of the spark timing can allow much more freedom and effectiveness in how you use fuel. When you get to that point, we can talk about ignition options.

Thats with a twist. If the distributor is handling the timing now with vacuum and weights, those need to be locked out if you want to use the old coil trigger as crank signal.

But i've gone the same route with my old ford. Was so lucky i could find one from a newer model but with same engine. Replaced the points and advance-systems with a fixed 4 window disc and a hall sensor, and then used a golf mk3 coil. Drives really well now, great advantages over the stock in regard of cold idle and driveability really

[Jonikopsuka]

I have now managed to take a closer look at the parts I currently have at my disposal.
Injectors are A46-00 Grey tops from a 2nd generation Subaru as are the fuel rails. I don't know if these are high or low or power control but if I have read the wiki correct then it doesn't matter. Just means more work if they are wrong kind?
TPS is a 3 wire so I think it will work fine. I also have an idle air control valve but I believe it is not needed and would add complexity.
IF I decide to go with coil ignition I have a Diamond F-569 12V ignition pack. I think it has 2 coils as there are 2 bulges with 2 electric wires coming out of both bulges.
Lambda I do not yet know but purchase is always option.
Do I need to get more temperature sensors unless I want to not see Coolant on the dashboard? Volvo has coolant temperature connected to the dashboard.
Last three question are can I use a single oil pressure sensor for both dashboard and ECU? I think it is important for both ECU and myself to know if oil is gone.
Can I program or set multiple conditions in the ECU when it will turn on custom light in the dashboard? I would want this to act like orange engine light on new cars to show something is wrong.
Is it hard to make cheap chinese engine speed dial work with the ECU? Currently the Volvo does not have engine speed dial and good dynamo testing requires engine speed dial.

Thank you in advance for helping.

[PSIG]

Lambda I do not yet know but purchase is always option.

I do not mean this in a bad way, only an observation; but if you do not know the value of wide-band O2, and if you are not an expert tuner, then you are not likely to know how to tune well or quickly without one. I hope you see my meaning. As to your other questions, most of them are "yes", but involved, and you are risking "project bloat". What should be a weekend to a week job to EFI your engine, can easily turn into weeks or months for things are are not immediately or ever necessary.

I would suggest you approach your project in stages, doing only necessary stuff to make it run well. If you have problems with oil pressure in your engine, then maybe make that mod next. Then add more warnings or functions as you get each one to work well. This will ensure quick progress, and more understanding from running the converted engine that you don't have yet. Keep going!

[Jonikopsuka]

I do have a spare lambda from the spare parts Subaru but that is a narrow band and as I understand those aren’t all that optimal especially considering that because of the age of my Volvo it never came with a catalytic converter.
I know that wideband sensors can be a tad bit expensive but I did find a Bosch LSU4.9 unit from a retailer near me and they are selling them for 90€.
For me this is not a high priority project at the moment as the Volvo runs and drives fine but I’m sick and tired of the stock carburetor. The engine doesn’t have any oiling problems as of now but it does have 312 thousand kilometers on it so it is getting somewhat old and that’s why I’d like for both the ECU and myself to know if it suddenly loses pressure and maybe just maybe do something like low oil pressure for 1 minute = engine shutoff just as a failsafe. I’m not gonna go and play Frankenstein on my daily driver until I get around to changing the engine on my ”working” Subaru so I at least have a car to use.