ecu compatiblity apex'i powerfc and other q's vrg3 look here

[azn2nr]

ok looking at the pinout diagram that just because its named 94 wrx im asuming its all correct.

all the wires match with the excption of 3. radatior fan 2 and ignition 3 and 4. im assuming that this is because on the wrx they maybe had gone to pack on plug instad of coil pack. unless they didnt which would be odd.

so how do we solve this problem??? other than thoes three wires by all means the powerfc should be able to run the motor and for a standalone with a hand heald tuner its dirt cheap. is there a way to compensate for thoes 2 wires by doing a pack on plug conversion or running 4 wires off the pack instead of 2?

radatior fan shouldnt be a problem.

so imput people. bascily 2 wires to make standalone a possibility for all of us. even the automatics.

[vrg3]

Yes, the only external wiring differences are the extra radiator fan control pin (which on EJ20G-equipped Legacies/Liberties is used to control the intercooler pump) and the extra two ignition channels. And yes, the reason there are four ignition channels is because there is one coil per plug.

What's the problem you're referring to? Are you asking how you can use a PowerFC, and saying that the PowerFC only drives two ignition channels? I would expect it to be able to drive four... don't people with 4-channel ignition systems use them?

It is possible to convert and EJ20G to a coil pack setup using spark plug wires if necessary.

[azn2nr]

somehow im thinking that the power fc base maps wont be able to run the car with 2 drive chanels. though it does have 4 because its plug and play. im tryin to see if theres a way to use pfc as plug and play with upgrades similar to oe ej20g equiptment.

so bascily the problem is, how do you convert from coil pack to pack on plug???

[vrg3]

A few people who swapped EJ20Gs into their Legacies have done it so they could use their stock ECUs. You just have to mount the coil pack somehow and use some appropriate plug wires. And if you're doing it on a car that was originally equipped with an EJ20G, you'll have to wire in a 2-channel ignitor.

[azn2nr]

yeah but thoes people went from pack on plug to coil pack. right???

[vrg3]

Oh, whoops, right... you're asking how to go the other way? I'm a little confused.

What exactly are you trying to do? What kind of car? Which engine? Which wiring harness? If you explain what your goal is maybe I can help.

Do you have a link to the specs for the PowerFC?

[mikec]

If the PowerFC wants to drive 4 ignition channels, can't you just run channels 1 and 3 to the front coil, and 2 and 4 to the rear? Won't that basically run the coil / engine like the stock ECU does (waste spark)?

Or am I missing something in the question too?

[vrg3]

I dunno. You might be able to easily combine the signals, or you might not, depending on dwell times.

[azn2nr]

every site just copys the apex'i site on info which admitaly isnt verry hepful on specs.

the pfc as far as i can tell wants to have 4 ignition channels since its based to plug into where the ej20g ecu was. i want to use it on my legacy so id want to go to the 20g ignition style of 4 channel instead of 2 using a pack on plug system. im beginning to think that it would take rewiring the whole system unless i can program the pfc to waste spark instead of what its already programed to do

[vrg3]

Okay... so you want to use an ECU meant for an EJ20G on an EJ22T.

Converting to coil-on-plug would be hard, primarily because you'd have to modify the head or the valve cover to properly hold a coil-on-plug coil.

What I would suggest, if you do need to convert to 4-channel ignition, is getting four individual ignition coils. RS Liberty owners often do this -- they get four high-energy Bosch ignition coils, find places to mount them in the engine bay, and run spark plug wires between them and the plugs. In our case it's even easier because our stock wires should fit perfectly.

Then you need a 4-channel ignitor, or two 2-channel ignitors. That should be easy enough, I think.

I'm not sure how critical matching of all these components is... The easy way out would be to use an MSD DIS-4 or similar to drive the coils, cuz then it doesn't really matter since it'll just spark the &%$# out of the mixture no matter what.

When you're ready to do this and have selected the parts I can give you advice on how to wire it up.

[azn2nr]

seems more complicated than i had hoped, if i dicide to go this route ill deffinatly let you know

[azn2nr]

ok a few last ideas. if the wires that are usualy suposed to control 3 and 4 ignition arent wired, if i put the 2 pins that are missing and tap them into the harness it will still be waste spark but on a different control level.

also is there any comunication between teh ecu and the tcu? kelly was telling me that there was and therefore standalone was impossible with autos, but acording to all the trans swap and pinouts ive see theres only 1 wire that just lets the ecu know if its auto or manual so in my mind there shouldnt be a problem.

[vrg3]

if the wires that are usualy suposed to control 3 and 4 ignition arent wired, if i put the 2 pins that are missing and tap them into the harness it will still be waste spark but on a different control level.

I don't understand.

also is there any comunication between teh ecu and the tcu?

Not really, on our cars... 90-92 non-turbos had the ECU reporting barometric pressure to the TCU, but that's it. The TCU and ECU do share some sensors, though, and it's plausible that for the VSS and idle switch the TCU may not understand the signal without the ECU's internal pull-up resistors, but that's easily remedied.

Later models do have some communication between the ECU and TCU though.

[azn2nr]

ok so the idea is take pin F47.9 out and putting it in F47.8. then you put an extra pin into F47.9 and splice it into F47.10. then put an extra pin in F47.7 and splice it into F47.8 and then plug in an autronic or powerfc for an ej20g. the ecu will still be using 4 channel ignition control but it will be feeding a 2 channel waste spark system.

do the turbo ecu's give any signals to the tcu or is it just the non turbo models. and how easily woudl the vss and idle switch be remedied.

[sammydafish]

Okay... so you want to use an ECU meant for an EJ20G on an EJ22T.

Converting to coil-on-plug would be hard, primarily because you'd have to modify the head or the valve cover to properly hold a coil-on-plug coil.

What I would suggest, if you do need to convert to 4-channel ignition, is getting four individual ignition coils. RS Liberty owners often do this -- they get four high-energy Bosch ignition coils, find places to mount them in the engine bay, and run spark plug wires between them and the plugs. In our case it's even easier because our stock wires should fit perfectly.

Then you need a 4-channel ignitor, or two 2-channel ignitors. That should be easy enough, I think.

I'm not sure how critical matching of all these components is... The easy way out would be to use an MSD DIS-4 or similar to drive the coils, cuz then it doesn't really matter since it'll just spark the &%$# out of the mixture no matter what.

When you're ready to do this and have selected the parts I can give you advice on how to wire it up.

An other alternative on the same concept would be to use coils with integrated igniters. On my Supra, I run GM LS1 coils. They have the igniter built into them and are hella strong. Because the igniter is built right in, the ECU can drive them directly.

[vrg3]

Jason - You can't just splice the wires together.

I forgot about one signal in my earlier post -- the tachometer signal. The ECU does send its tachometer signal out to the TCU. This is the same signal that actually drives the tach on the gauge cluster, though, so I would expect an aftermarket ECU to still produce it.

For the VSS and idle switch -- if the new ECU doesn't connect to them, just connect a 10K resistor between the signal line and the MAP sensor power supply pin, and you should be fine.

Junior - Huh, neat... Are the ignitors on the LS1 coils simple dumb ignitors (i.e. just big power transistors)? Cuz that's what Subaru systems use, but I seem to remember at least some Supra ignitors being more active than that.

[azn2nr]

Jason - You can't just splice the wires together.

.

well i just thought that since our ecu already has 4 ingnition signals going thorugh 2 wires that if you spliced the wires together that it woudl be the same concept except you wouldnt have to change the ignition system or the new ecu.

[Legacy777]

Just to chime in. I accidently cut the tach signal to the TCU......the trans still worked, but shifting was very laggy, and things just didn't seem right.

[scuzzy]

I actually started looking at this last night and comparing the 1996 Impreza's wiring harness to the 1994 Turbo's harness.

Of course the difference is the varances in the ignition system.

Since there's nothing occupying the spots at pins 7 and 8 (and the Radiator fan 2 control can be wired in)

It's conceiveable that you should be able to modify your standalone ECU (the Autronic) in the software, at the very least, to convert it to a WS ignition system.

From there, it's still plug-right-in.


If I remember correctly, our ignition system is 2-coil double end wasted spark. correct me on this because it can be one of two different wasted spark methods. Single end four coil or double end two coil (I assume double end two coil)

I havn't actually had the ignitor in my hand (which drives the coilpack) but looking at the coil pack, there is one supply +12V switched with two grounds.

if I held the ignitor, and looking at wiring maps, I could tell 100% for sure.


but anyway.


I'm going to fire off an email to Autronic and ask them how compatable the PnP Autronic ECU is when converted to our cars, since that beats the fuck out of wiring; and how easy it would be to tune it for our engine and change it to a WS setup.

since it's about midnight in aussyland, I probably won't hear back from them till Monday, but i'll keep everyone posted.

[vrg3]

Jason - Our stock ECU outputs two ignition signals. One for cylinders 1 & 2, and one for cylinders 3 & 4.

scuzzy - Yes, it's double-end twin-coil.

[azn2nr]

yeah i realize that. what im saying is that the ecu's for the ej20g have 4 ignition signals so you can try to A) merge the signals in the software or B) merge the signals in the wiring harness which is what im sugesting. i really dont see why it wouldnt work.

[vrg3]

Good luck with that.

[azn2nr]

is there something that could go majorly wrong that im missing or what???

[scuzzy]

David,

The Plugin board runs wasted spark with the 1996 model engines. Two ignition outputs from the ECU drive two pins each on the connector. Ignition output 1 is connected to pins A7 and A9, Ignition output 2 to pins A8 and A10. So there is no problem.

Any injectors you have can be controlled by the ECU without problems.

This ECU can control boost or idle control, but not both together. There is a jumper on the board to select either. If idle control is important to you then fit an external boost controller.

(At current exchange rates, our cost for the ECU + shipping is $1520. plug right in, do a little tweaking. done. Autotune also comes on the board)

Ray Hall.
Autronic Fuel Injection

[scuzzy]

a little clarification on that ignition output.

On 1996 WRX:

Pin A7: Ign Ctrl 4
Pin A8: Ign Ctrl 3
Pin A9: Ign Ctrl 2
Pin A10: Ign Ctrl 1

On Legacy:

Pin A9: Ign Ctrl 3/4
Pin A10: Ign Ctrl 1/2

Subaru firing order is 1-3-2-4

When our ECU fires the two-channel coil, this is how the dance goes.

Fire on pin A10 - Spark on Cyl 1 & 2 - Cyl 2 on Exhaust stroke.
Fire A9 - Spark on 3 & 4 - Cyl 4 on Exhaust
Fire A10 - Spark on 1 & 2 - Cyl 1 on Exhaust
Fire A9 - Spark on 3 & 4 - Cyl 3 on Exhaust

So essentially two plugs fire at once, one spark is wasted (hence wasted spark setup); to combat the wasted spark effect (the plug on the exhaust stroke will have lower resistance and most of the energy goes there) the plugs are resistive, to deliver an equal (or near equal) spark every time.

Now, when the 1996 WRX ecu drives spark, it does it on a non-wasted spark setup, there are four outputs for four channels and each is fired one at a time for spark energy.

However, Autronic's implementation of this is to drive two channels with one ECU output.

The first ECU output is on Channels A7 and A9 (Ign control 4 & 2 on the 1996 WRX)
The second output is on channels A8 and A10 (Ign control 1 & 3)

and here's where I get confused, because the firing order is the same. 1-3-2-4

So if the Autronic were to fire CH2, you'd get spark on 1 and 3. If we were at the top of our compression stroke on 1, we'd fire on 3 which has just bottomed the intake stroke and has a cylinder full of fuel - a fire on 3 at this point is damaging to the engine.

so there's some confusion going on in here in regards to the 1996 WRX.

However, in our situation; if CH2 were to fire on the Autronic, it would light up our only connected pins, Pin A10 (Cyl 1 & 2), CH1 lights up pin A9 (Cyl 3 & 4) - so the setup will work perfectly, it'd work just like it would factory.

Perhaps the guy who emailed me was confused when he said they ran wasted spark on the 1996 WRX with two outputs controlling four channels, because the way the outputs are wired, you'd blow your engine up.

Perhaps he meant that it can be configured for WS setup versus how the 1996 WRX is setup, and it'd work just fine for us.