Coil Pack (DIY - Buick V6) firing order...

[Targa44]

My coil pack (DIY) for a 6 cylinder shows the following order (stamped on the coil pack)... additionally, my firing order is 1-6-2-4-3-5.
6 - 3
4 - 1
2 - 5

....just had an aha! (I think). The reason my pairings worked on an identical car as mine is because of the direction of the coil firing. It must fire in the 2 - 5, then the 4 - 1, and finally 6 - 3 order or (call it) going up the coil. So, if my firing order is:
1
6
2
4
3
5
there's the repeat sequence.

kj

[Dennis930]

kj,

Megasquirt uses the firing order that you enter into TS. For wasted spark on your engine, when the missing tooth on the crank wheel passes the crank sensor, it knows that either cyl#1 or cyl#4 is ready for a spark event. MS sends a spark signal (Spark A) to the coil pack coil for #1&4, which causes a spark on those two cylinders, one in compression, the other in exhaust. 360* later it does it again for the same coil. 120* after Cylinder #1 and #4 spark event has occurred, the spark event for cylinder#6 & #3 occurs, then 120* after that the spark event it occurs for #5 & #2.

This coil pack could be used on an engine with a different firing order, you just have to connect the plug wires to the corresponding poles on each coil and enter that firing order in TS.

[billr]

No! MS always fires the spark (and injector) outputs A-B-C-D-E-F... Those must be hard-wired to the proper coils/injectors for your firing order. The settings in TS do not have much meaning.

[Targa44]

I'm not in a position to create an "argument" because I'm just too new at this. But, I kind of agree with both. I understand and had thought like Dennis about the 'even fire' nature of the engine... i.e. every 120* firing. And, since it's batch, it fires in pairs. But as Bill says, I'm not quite sure about the relevance of the firing order settings in TS yet.

Will TS see my settings and tell the coil to fire in the same pairings as the coil? .... as long as I've connected the coil wires to correspond with what I've entered in setting. So, my theory above isn't correct - the coil pairing firing order could be in the other direction from what I'd theorized -- based on how I listed the firing order setting in TS? Is that it?

Bill - the outputs a-b-c-d-e-f.... is that batchfire? Or, you're just saying to hardwire the coil # to the corresponding cylinder. When we get together, I'll show you how the kit maker labelled the coils. This might be interesting when trying to set up timing.

I'm still in the slow lane but I find some of the nuances interesting to sort out.

thanks folks,

kj

[billr]

Sorry, I should have made it simpler. Your firing order is 1-6-2-4-3-5 so...

For that three coil wasted-spark setup you can use:

A => coil 1/4 it makes no difference which towers on the coil the 1 & 4 plug wires go to (generally speaking, that Saturn system I mentioned before is one known exception)
B => coil 6/3 ditto, either tower for either plug wire
C => coil 2/5 ditto, either tower for either plug wire

If you had COP, wiring would have to be:

A => coil 1
B => 6
C => 2
D => 4
E => 3
F => 5

Edit: it is pointless to worry about this until you have selected what coil driver (igniter) you are going to use. Wiring the drivers between the MS3X and coils is where this will all be "hard-wired" in the correct order; and the exact pin-outs can't be specified without knowing what the drivers are. By the way, injectors follow the same scheme: 1-6-2-4-3-5 are wired to injector drivers A through F respectively, for "full sequential".

[Dennis930]

Bill,

I stand corrected about MS firing sequence being a hardwired to the proper spark output. Is he using a MS3X board?

[billr]

Yes, I think so. I will be taking a peek at what is there soon. Then we will at least have the "two sets of eyes" on it.

[billr]

I think we made good progress today, the engine will fire and run now. The OP will post a picture of a MAP sensor mod (second sensor scabbed on) and the MSQ/MSL.

The fundamental problem is that there is no MS3X, so settings calling for MS3X spark and injector outputs were bogus. It is using the standard injector drivers and LED spark with two extra BIP373s installed in the MS case.

The (DIYautotune) cable from the MS to relay board has no wires for pins 12-19. The OP was told they aren't needed, and I know that is technically correct, but I'm wondering if more grounding of the MS is desirable because the three ignition drivers are in the box.

Note to OP: set spark timing to "fixed" (I suggest 30 deg, since you have a convenient mark there) and recheck timing with the engine running and revving it up. The timing should be stable with "fixed" even with the wild rpm/MAP oscillations you presently have.

We made no attempt to fuss with the injector config. I'm told they are 12 ohm, so left PWM off, and we think each bank is on a separate driver. He needs somebody familiar with this type engine to help with how to best config those injectors and how to control them (simultaneous, alternating, etc.).

No IAC or TPS here, I told him to jumper the TPS signal to ground so that would not drift around.

[Targa44]

Bill beat me to it - thanks again Bill. Quick note on 4' relay harness wiring - DIY omits wiring 12-18. I think pin 19 is used for sensor ground. I also wonder if it wouldn't be worth it to go ahead and add wires 12-18 as the board does have mods and the pigtail this setup came with was completely wired pin to pin connector. It "might" be one of my issues.
Is IAC the same as AAR (auxiliary air control)? ... because it has a bi-metal valve that opens/closes based on temp to control add'l air below the throttle plate.

Attached are the MSQ and MSL files from today's exercise. Wild oscillations as seen... Photo of the board to follow.

[Targa44]

Pic of the backside... if the quality is too poor, I'll go back out and pull out the unit again and make a better image. Question is about extra MAP sensor (black) in upper right. What's the purpose?

thanks,

kj

[jsmcortina]

Almost certainly that is for baro.

James

[billr]

It isn't clear from the picture, but the lead (on that added sensor) that is towards the bottom in the picture (away from the yellow wire) has been clipped. Does that seem right; is it common for sensors like that to not use all leads?

[kjones6039]

Bill has much better eyesight than me (of course he is much younger also) but I would ask the same question...........

Ken

[billr]

Well, I got to see it in person, with magnifier and bright light. There are two of you "kj" guys here, I may get confused!

Kj-the-OP: You may have to open that up and lift that sensor to read the P/N on its backside, and to trace where that yellow wire connects to. Actually, make a sketch of the whole resistor and yellow wire path.

As to that short length of un-shielded cable from the CKP sensor to the relay board... I would eliminate that by cutting the connector off the sensor cable and connecting that cable directly to the relay board. I think that would make the wiring neater and eliminate one connector and eliminate any possibility of noise getting in on that un-shielded length. Your relay board it so easy to access that having it "direct wired" without a connector would make replacement of the CKP sensor (if ever needed) hardly any more trouble than just unplugging a connector. Note to all, though: there is no indication of an actual problem from that un-shielded cable at this point.

[jsmcortina]

It isn't clear from the picture, but the lead (on that added sensor) that is towards the bottom in the picture (away from the yellow wire) has been clipped. Does that seem right; is it common for sensors like that to not use all leads?

That sensor only uses three pins. +5V, GND, signal. Check the V3.0 mainboard schematics in the manual.

James

[Targa44]

I think I need to move to a different thread name as this title is misleading and not related to current issues and doesn't request tune help. New thread starting Aug. 3rd titled "Tune help needed: engine running w/wild surging"

kj