Wasted Spark Help

[ErOR]

Hi.

Have setup wasted spark with holden coils on a R32 S1 RB25 but now the issues is that the ECU is getting two pulses for no1 cyl spark as the cyl1/6 and cyl1 sensor wire are bundled. It's quite obvious when under a timing light, the timing is jumping all over the place.

I've spend a few hours trying to remedy this with a diode but no luck what so ever, talk about a waste of time...

Anyone have experience or knowledge about fixing this, I really need to sort this out. The car goes fine but can tell something is not 100% with the ignition.

Cheers!

[Ben C34]

You will get 2 sparks when you would o ly have had one previously, that's the wasted bit, firing on the tip of the exhaust stroke also.

Why did you do it?

[ErOR]

Yeah I understand what's going on, but I need to make it so cyl6 trigger doesn't affect the sensor wire as the that tells ECU when cyl1 is firing, this is how I understand it.

I did it because it was under $100 and my coils were about done.

[Ben C34]

Nothing tells the ecu when a coil fires.

The ecu tells the coils.

The sensor wire is there for checking timing, doesn't work properly with the majority of timing lights anyway

Seeing as you have plug leads now that's how you check the timing, by clipping between the coils and cyl1

[GTSBoy]

What he said ^.

The input to the ECU telling it "about" cylinder 1 is in the CAS.

The ECU will output on 1 of its 6 ignition according to what angle the CAS says the engine is at. The appropriate coil will fire. When you go wasted spark, you now have 2 outputs from the ECU firing a coil.

I do not know if the stock ECU is actually going to be happy with having outputs effectively paired together, and maybe you do indeed need a set of 6 diodes to stop them backfeeding and causing it to go emo. Or maybe it will be fine.

It sounds like you have Holden coil packs that do not have their own inbuilt ignitors and you are using the Nissan ignitor pack on the top of the engine. (I gather this because you talk about using the black wire loop to trigger the timing light). In this instance, that ignitor module will in fact be isolating the commoning up of coils from the ECU, so what I said above about the ECU being happy/unhappy about it probably goes away.

In which case, the whole thing collapses to what Ben said. If you are trying to trigger the timing light from the loop, you will be getting 2 pulses per ignition cycle on it, instead of just the correct one for cylinder 1. Which will give you crappy results. If you use the normal inductive trigger on a plug lead, you should be fine.

[ErOR]

Here is how the setup is wired up, As far as I understand the red wire is sensing when cyl1 fired so the ECU can set electronic timing but since cyl6 trigger wire is also connected to this it upsets the ECU (Please correct me if I'm wrong!). Firing order is 1-6 3-4 2-5 so the there's a second pulse not even a second later. I tried connecting cyl1 trigger wire and the red wire together -> diode -> cyl6 trigger wire -> coil but that resulted in cyl1 not firing even though it had spark.

Timing was checked via plug lead of course. Timing is jumping about 4 degrees backwards and forwards couple of time every second through the rev range.

Gonna go see a sparky tomorrow and get some advice.

Edited May 7, 2016 by ErOR

[GTSBoy]

Here is how the setup is wired up, As far as I understand the red wire is sensing when cyl1 fired so the ECU can set electronic timing but since cyl6 trigger wire is also connected to this it upsets the ECU (Please correct me if I'm wrong!).

We already did that.

[Scott Black]

Oh no....your using the 6 cylinder commodore coils.....please tell me atleast your not attempting to use the ignition module that's ment to sit below them? If so forget it. If however your trying to use just the coil packs(unsure why as there crap and fail so much and I'm unsure if the dwell is even compatible) then yeah you need to bridge the inputs to the ignitor then only use 3 of the outputs yet it won't effect the timing light as its always going to be firng at the same time relative to crank position

[Scott Black]

Also for any one wondering. The v6 commodore uses 3 twin output coils sitting ontop of an ignition module(not ignitor) so literally only fires 3 coils yet each coil being twin post does two cylinders. Ugly setup.

[ErOR]

Oh no....your using the 6 cylinder commodore coils.....please tell me atleast your not attempting to use the ignition module that's ment to sit below them? If so forget it. If however your trying to use just the coil packs(unsure why as there crap and fail so much and I'm unsure if the dwell is even compatible) then yeah you need to bridge the inputs to the ignitor then only use 3 of the outputs yet it won't effect the timing light as its always going to be firng at the same time relative to crank position

The ignition module is stock s1 rb25 one and the coils are VN I believe. Dwell time is probably not right but I'm just trying this out to see how I go then later I'll make a proper setup.

Bridge what inputs? It's impossible to adjust timing right now.

[GTSBoy]

Bridge what inputs? It's impossible to adjust timing right now.

as written pretty clearly in SB's post.

bridge the inputs to the ignitor then only use 3 of the outputs

Edited May 8, 2016 by GTSBoy

[Scott Black]

The ignition module is stock s1 rb25 one and the coils are VN I believe. Dwell time is probably not right but I'm just trying this out to see how I go then later I'll make a proper setup.

Bridge what inputs? It's impossible to adjust timing right now.

Essentially your saying I want to change injectors yet don't want to worries about pulsewidth just see how I go at first. Dwell is the most important setting for the coil, to little and it won't run to much and you destroy your coils.

[ErOR]

as written pretty clearly in SB's post.

bridge the inputs to the ignitor then only use 3 of the outputs

that makes no sense

Did you not realise yet that I'm trying to learn and am a total newb?!

[Ben C34]

You might be in too deep here

[GTSBoy]

that makes no sense

Did you not realise yet that I'm trying to learn and am a total newb?!

We'll ignore the total newb aspect, because using wasted spark coils is already a sure sign of that.

Let's start at the beginning. There is only 1 ignitor we're talking about. It is the Nissan one that lives(d) on the top of your coil cover. Scott's instruction was to bridge the inputs to that ignitor. That means, for each of the ECU outputs (that I first posted about) you join together the pairs that fire on the same coil. Join 1 + 6 from the ECU for example. You do this on the INPUT side of the ignitor. Then you only use 3 of the ignitor channels. So you hook up the paired 1+6 signal to either the 1 or 6 channel on the ignitor and then you take the output of that to the coil that you need to trigger - making sure that you don't pass it through the Holden ignition module on the way to the coil primary.

But in reality, the smart way to do this is to throw the waste spark business in the bin and buy some decent coils.

Edited May 9, 2016 by GTSBoy

[KiwiRS4T]

Save up for some OEM or Splitfire coils.

[Guilt-Toy]

the firing order is 1 5 3 6 2 4

So you need to double up these outputs coming out of the ecu

1 -6

5-2

3-4

Together going into the ignitor.

Then out of the ignitor you connect the 3 channels to the wasted spark coils. do not connect any other wires to these.

In this setup you are better off buying a good 3 channel ignitor to replace the standard nissan one (alot less confusing)

Also bare in mind that commondore v6 coils need a massive dwell to charge up, if you are running a aftermarket ecu this is OK but it will not work with a standard ecu.

[Meathead]

We'll ignore the total newb aspect, because using wasted spark coils is already a sure sign of that.

Let's start at the beginning. There is only 1 ignitor we're talking about. It is the Nissan one that lives(d) on the top of your coil cover. Scott's instruction was to bridge the inputs to that ignitor. That means, for each of the ECU outputs (that I first posted about) you join together the pairs that fire on the same coil. Join 1 + 6 from the ECU for example. You do this on the INPUT side of the ignitor. Then you only use 3 of the ignitor channels. So you hook up the paired 1+6 signal to either the 1 or 6 channel on the ignitor and then you take the output of that to the coil that you need to trigger - making sure that you don't pass it through the Holden ignition module on the way to the coil primary.

But in reality, the smart way to do this is to throw the waste spark business in the bin and buy some decent coils.

Did you have a charisma by-pass per chance?

[GTSBoy]

Why pick on that post? It's just about the nicest one I've done this month!

[Meathead]

Why pick on that post? It's just about the nicest one I've done this month!

About average I reckon, for you.

Feel sorry for newbies getting barked at by resident experts like you! haaaa

Edited May 9, 2016 by Meathead