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-   -   Have you measured when the injectors... (http://www.mazdaspeedforum.org/forum/forum/f633/have-you-measured-when-injectors-125087/)

djuosnteisn 10-10-2009 05:21 PM

Have you measured when the injectors...
 
The fuel system (injectors) is not adequately sized for producing more than around 350-380whp. At that point you're also looking at very poor combustion and efficiency in the upper RPMs.


Here is a summary of this thread

We have measured the injectors for the mzr disi: This thread is littered with videos and pics, and the first 3 pages are definitely a good read if you bored, and a must read if your going to be measuring the injectors yourself.
Some facts:

We can update the pinouts for the MS3 if anyone wants to provide me with that data.
Pinouts on the ecu for a MS6 (you can use the wot box install guides for pinout locations)
Ignition coils:
cyl 1 - 3W
cyl 2 - 3X
cyl 3 - 3Z
cyl 4 - 3AA

Crank sensor - 2C

Cam shaft sensor (i didn't use it) - 2E

ECU injector control line to injector driver
cyl 1 - 3B
cyl 2 & cyl 3 - 3E & 3H (haven't confirmed exactly which is which)
cyl 4 - 3K

Injector wire colors on the injector plug i keep probing in the various pics and vids
cyl 1 - red
cyl 2 - brn/wht
cyl 3 - grn/wht
cyl 4 - blue


The crank:
Confirmed it is a 60-2 wheel. So 60 teeth with 2 missing. (The regular mazda 3 duratec has a different crank).
See the picture below. The engine rotates clockwise. So that means the missing tooth/gap is 120 degrees BEFORE TDC on cylinder 1 compression.
http://www.mazdaspeedforum.org/forum/foru...rank-wheel.jpg

Firing order is 1 3 4 2.

The 4 injectors are controlled by both a + & - control rails. The - controls are specific to each cylinder. The + controls are shared between cylinders 1-4, and 2-3.
http://i359.photobucket.com/albums/o...Injsignals.jpg

The injectors are likely controlled with logic like this:
http://i359.photobucket.com/albums/o...torcontrol.jpg

If you monitor one of the injector lines (not ecu control line, but direct line to injector) you will see both the actual opening event, and also the + switching between 1-4 & 2-3 connection. The injector is not spraying twice though.


Spark:
Quote:

The spark actually happens at the end of the pink trace (falling edge). When the signal is high, it is charging the coil. When the edge falls, the spark happens. I counted about 18 crank pulses from the missing tooth to the end of the spark event in this picture. Every crank pulse is 6 degrees. So 6*18 = 108 degrees. Since spark happens at 10 degrees before TDC, that means it is 108+10 = around 118 degrees from the missing tooth to TDC. Which is correct. Nice capture!
http://i359.photobucket.com/albums/o...otchcount1.jpg
During shifts, the injector may sometimes spray after the spark event.


HERE'S THE JUICE OF THE THREAD
When fairly bolted, and near redline, the injection cycle will extend all the way through the intake stroke and into the compression stroke, and depending on the fueling requirements, it'll get damn close to the spark event. This has some serious implications:
- Fuel injected from the injector depends not only on the fuel rail pressure, but the differential pressure between the fuel rail and the combustion chamber. As you start spraying further and further into the compression stroke, the injector requires more and more time to spray a given amount of fuel. You can almost think of this as a redline for our injectors, higher rpm's may not result in higher power beyond a certain point.
- For proper fuel atomization, time & fresh oxygen is required. We have a swirl type injector injecting at around 12MPa in a wall guided system. This is pretty much AS BASIC as it gets with direct injection.
Quote:

I have an SAE paper in front of me quoting 3ms for complete vaporization. At 6000RPM 3ms = around 110 crank degrees. If we are still spraying let's say even 40 degrees BTDC, that means unvaporized fuel will exist well past 70 degrees after TDC and by that point it's too late to get power out of it. We get soot.
- Mazda's Direct injection is limited to a maximum of 50% duty cycle, consisting of the intake stroke and compression stroke.


Potential fixes for a maxxed out DI fuel system:
1) Bigger injectors
2) Secondary fueling
3) Increasing fuel pressure



-----------------Here's the original thread, enjoy!--------------------

http://img230.imageshack.us/img230/8384/1255240665.png


Okay. So today i attempted to measure when the injectors open. I still have no clue when they open.

Time for lex and 06speed6 to chime in. I'll leave all my wires in place so i can continue measuring any additional shit anyone wants, just need some help gaining my bearings.

From the beginning:

I wanted to measure 3 different events, Crank Shaft sensor, ECU injector ctrl line for cylinder #1, and ECU spark ctrl line for spark #1.

For the crank sensor line, i used the exact same one as used in the wot box, here's their install pic:
http://www.npcompleteperformance.com...full;init:.jpg

For the spark line, cylinder 1, i used pin 3W from this install pic for the wot box:
http://www.npcompleteperformance.com...full;init:.jpg

The injector circuitry was a bit more difficult, and i got a schematic from Jon at N2MB performance (Jon rocks the shit, good guy).
http://i359.photobucket.com/albums/o...injectors1.jpg

You can see the injector driver module in lower left hand corner. I assumed, that the indicated lines were control signals from teh ecu, because they map all the way back to it.

http://i359.photobucket.com/albums/o...injectors2.jpg
http://i359.photobucket.com/albums/o...injectors3.jpg

I made up some handy probe tools to stab the wires, saving me the trouble of splicing and stripping (but i do like to strip ;) ).
http://i359.photobucket.com/albums/o...n/_MG_9455.jpg


I had no clue what ctrl line controlled what injector, so set up my scope and mapped them by monitoring both the actual drive circuitry with the ecu control logic. *edit* I had incorrectly mapped the ecu control signals. I had chosen cylinder 4 for 1, read below posts for clarification.
All these pictures look the same, but basically it was me matching injector driver line to ecu control line.
http://i359.photobucket.com/albums/o...n/_MG_9459.jpg
http://i359.photobucket.com/albums/o...n/_MG_9460.jpg
http://i359.photobucket.com/albums/o...n/_MG_9461.jpg
http://i359.photobucket.com/albums/o...n/_MG_9462.jpg

So thought the universe was great, and lady fate was on our side. I called my buddy adam (koukis14) to come over and video the scope for me. I didn't really take a hard look at any of the traces on the scope yet, just knew that everything was hooked up and working right, car started, scope powered with the inverter etc.

Once he got here, we started studying the traces. Shit didn't seem to "add up".

important stuff
Here's a pic of the scope trace we were staring at:
http://i359.photobucket.com/albums/o...scopeshot1.jpg

Ch 1 is the crank (yellow), and as i suspected, it has data for many many sub-degrees.
You can see the "gap" section in, which maybe corresponds to the missing tooth lex mentioned.

Ch 2 (blue) is the ecu's ctrl line for the injector on cylinder 1 (assuming the pdf i got from jon is accurate, which i'm not 100% sure since it's from a source other than mazda).

Ch 3 (pretty pink) is the ecu's ctrl line for spark for cylinder 1, base on above wot box schem.



The pic shows something that is not possible (or at most, completely illogical), here's why
-Why would spark happen before the injector?
-Why would spark happen after TDC, assuming the gap in the crank signal = TDC? That means it'd either be advanced by like 360 degrees or retarded.


So we decide to start probing the actual injector driver along with the rest of the stuff we had from the ecu, and we realized a few things.
- The actual voltage signal on the injector lines (the ones i used to correlate to ecu control logic) was happening twice as often as we thought, but it was outside the span of the scope window. So basically there was the spike like in the pics above, TWICE as often as the control signal from the ecu. I'm not sure if this has to do with the inductive load, or some circuitry in the injector driver module, but it was definitely happening twice the rate of the ecu logic.

- We also noticed that the cylinders 2, 3 & 1, 4 seemed to have injection events at nearly the same time. But maybe since the scope was picking up double the real injection event, 2 & 3 are actually 360 degrees out of phase (crank degrees), and 1 & 4 also 360 degrees out of phase (crank again), and the two groups out of phase by 90 or so. I'm not sure.

I can think of two ways the motor would run (i'm probably showing alot of noobness here), one where cylinders 1 & 4 and 2 & 3 fire together, out of phase from each other but firing in groups of 2.

or one where each cylinder fires 180 degrees (crank degrees) out of phase from all other cylinders, with only one firing at a time. If this is the case, then maybe i correlated the wrong injector to the wrong ecu event, and there should have been a correct ecu control event that makes everything else make sense.

Here's a video of the mayhem, taking forever to upload: In the vid you can see how there are 2 injector events for every 1 pulse from the ecu ctrl line, and how things would work beautifully with 2 assumptions:
1) the gap on the crank signal represents BDC instead of TDC. I have no clue on this
2) I had incorrectly mapped the wrong ecu ctrl line to real life injector pulse because there are 2 pulses for each ecu event, so you can assume the odd pulse is the legit one. Also if you go back and look at the 4 pics where i tried to match ecu logic with injection pulse, there are overlaps of the curves, with one jagged looking blue curve and both a flat and notched yellow curve. This was the double pulse event, but i didn't recognize it.


If anybody has actually read this far, then i know they care, lol, and i'll do whatever i can to fucking measure this right, but i need some directions from the seasoned folks here.
Take your time, digest what i posted, and ask any questions you want. I'm going to leave all the shit hooked up till we get the right measurements, and then i'm gonna go rip around like samsel with a scope on my forehead, lol.



Right now i'm going to go out and solder what i think is ecu control line #4, cause if i mapped them wrong originally, this would be the correct one. If it works, and shit looks dandy, i'll let everyone now and clean up this fail ridden OP.

memin 10-10-2009 05:27 PM

damn i can tell that you were bored

danesti 10-10-2009 05:28 PM

do work son...

Lex 10-10-2009 05:31 PM

NICE! The crank signal is correct. The spark signal is correct as well.

The gap in the crank signal is the missing tooth. I think there are 60 crank teeth in total with 2 missing. Crank your time scale a little bit and you will the many missing teeth.

Spark is correct because the event is happening close to TDC (the missing tooth on the crank at idle) It's around 10 degrees BTDC. The missing tooth might not be exactly at TDC although that is a little strange

The crank spins twice (720 degrees) per engine cycle. So the missing tooth in the crank signal you will see twice for every injector and spark event. The missing tooth you will see every 360 degrees.

So are you unsure if that's the right injector you probed?

From what I can see, it's happening on the exhaust stroke (after the power stroke). So something is up.

Very good stuff so far!!!

After u get inj 1 figured out, are you going to be able to drive the car under load?

Also, you can probe the spark right at the coil pack. The igniter has 1 power, 1 ground, 1 signal line.

jahman 10-10-2009 05:48 PM

LOL!!! at first I thought this was just some kind of joke. Then I saw all the real datalogs on this thing and im like wtf!!

Nice work...hope we get this figured out.

djuosnteisn 10-10-2009 06:08 PM

Quote:

Originally Posted by Lex (Post 333418)
NICE! The crank signal is correct. The spark signal is correct as well.

The gap in the crank signal is the missing tooth. I think there are 32 crank teeth in total with 2 missing. Crank your time scale a little bit and you will the many missing teeth.

Spark is correct because the event is happening close to TDC (the missing tooth on the crank at idle) It's around 10 degrees BTDC. The missing tooth might not be exactly at TDC although that is a little strange

The crank spins twice (720 degrees) per engine cycle. So the missing tooth in the crank signal you will see twice for every injector and spark event. The missing tooth you will see every 360 degrees.

So are you unsure if that's the right injector you probed?

From what I can see, it's happening on the exhaust stroke (after the power stroke). So something is up.

Very good stuff so far!!!

After u get inj 1 figured out, are you going to be able to drive the car under load?

Also, you can probe the spark right at the coil pack. The igniter has 1 power, 1 ground, 1 signal line.

I got the injector shit figured out.

Not sure why there is two pulses on the injector line from the driver to the injector, but there is. It's probably due to some sort of inductive fly back on the coils or some shit. Like a voltage when the current starts, and a voltage when the current stops, but why they're both positive is beyond me.

Regardless, i had cylinder #4 for cylinder #1. Here's a pic with the real #1 control line and the real injector pulse. Looks real good.
http://i359.photobucket.com/albums/o...eisn/good2.jpg
http://i359.photobucket.com/albums/o...eisn/good1.jpg

Yellow is crank, pink is spark, green is the injector control line from the ecu, and blue is the actual voltage on the injector line.


Only other discrepancy is the crank "missing tooth". I'm now 99% sure the missing tooth, or at least teh gap in my crank scope trace corresponds to BDC, not TDC. If you pretend like TDC is in between the crank pulse, then halaluya, things work out.

Some facts:
Pinouts on the ecu for a MS6 (you can use the wot box install guides for pinout locations)
Ignition coils:
cyl 1 - 3W
cyl 2 - 3X
cyl 3 - 3Z
cyl 4 - 3AA

Crank sensor - 2C

Cam shaft sensor (i didn't use it) - 2C

ECU injector control line:
cyl 1 - 3B
cyl 2 & cyl 3 - 3E & 3H (haven't confirmed exactly which is which)
cyl 4 - 3K


Injector wire colors on the injector plug i keep probing in the various pics and vids:
cyl 1 - red
cyl 2 - brn/wht
cyl 3 - grn/wht
cyl 4 - blue

Lex 10-10-2009 06:10 PM

How many pulses are there between each "missing tooth"?

djuosnteisn 10-10-2009 06:13 PM

Oh, and one more fact (i'll prob get double post merged, lol)

Fact:
Scopes are cool, fuck teh dashhawk.
http://i359.photobucket.com/albums/o...aloverview.jpg


Lex, i can't gain access to the injectors directly easily, cause they're so deep under the intake mani. I think my ecu control and injector pulse shit is finally legit. I just need to know for a fact if that pulse in my crank trace (yellow) corresponds to BDC, then it's all happyville.

Oh and i can most certainly drive the fucker like this, lolol. Adam and i will taker her our for some samselin tomorrow. Maybe i'll get a scope log of me beating a sti hahaha.

Lex, i was probing the connector that carried all the wires to all the injectors. I know cylinder 1 is passenger. I have a schem showing me the proper colors to all teh injectors, so i'm pretty confident in which one i was probing.

Quote:

Originally Posted by Lex (Post 333433)
How many pulses are there between each "missing tooth"?

I'll go out and start the car, enjoy a beer, and count. BRB.





And come on, a root beer of course, sheesh people.

Lex 10-10-2009 06:40 PM

EDIT: NVM - not a 36 tooth wheel !!

djuosnteisn 10-10-2009 06:45 PM

Counted 57 pulses between the gap (missing tooth). I didn't count either the low or high end of the missing tooth stuff, so i could be 58 or 59 depending if you want to count 1 or both of those event.

I think if you count both, and then allow for the "missing tooth" that gives you 60, and low-n-behold, you have each pulse = 12 degrees or so. (or 6 depending how you look at it, crank or cam).

Lex 10-10-2009 06:53 PM

1 Attachment(s)
EDIT: Confirmed it is a 60-2 wheel. So 60 teeth with 2 missing.

See the picture below. The engine rotates clockwise. So that means the missing tooth/gap is 120 degrees BEFORE TDC on cylinder 1 compression.

DJ, can you please get a zoomed in pic (smaller time scale) on the scope where we can count the number of crank pulses before/after the spark and injection events with respect to the missing teeth?

djuosnteisn 10-10-2009 06:56 PM

Ugh, not sure, i'll go start the ol car and look lol. Actually better yet, i'll take a pic of a close up, that'll help us find the right wheel maybe. BRB!

Here's ol' toothless mc'gee:
http://i359.photobucket.com/albums/o...ssingtooth.jpg


Don't mind the blurriness, it's the rootbeer.

FreeFlyFreak 10-10-2009 07:18 PM

So it looks like the Mazda DI has two injection events per combustion event, one squirt before ignition and one after.

superskaterxes 10-10-2009 07:20 PM

dustin your right about 1&4 firing together and so do 2 & 3, i knew i remembered seeing this from SU marks build.


djuosnteisn 10-10-2009 07:22 PM

Quote:

Originally Posted by superskaterxes (Post 333486)
dustin your right about 1&4 firing together and so do 2 & 3, i knew i remembered seeing this from SU marks build.

Negative, i'm thinking while cylinder 2 is on compression cycle, cylinder 3 is on exhaust. Same for 1 & 4.


But HUGE thanks for that vid, makes so much more sense now, lol.

JMEngineer 10-10-2009 07:23 PM

At this point it may have been easier to just get a Haltech platinum sport 2000 and tell the injectors when to open.

djuosnteisn 10-10-2009 07:27 PM

Quote:

Originally Posted by FreeFlyFreak (Post 333484)
So it looks like the Mazda DI has two injection events per combustion event, one squirt before ignition and one after.

I'm gonna step out on a fairly confident limb here and say Negative hombre.

A second event (at least from what the scope shows) would indicate fueling during exh strokes, and that's ludicrous. More than likely it's an inductive phenomenon with the way the scope was loading the line or something, but it's not real. We'll no more when we load the vehicle hopefully.

Lex 10-10-2009 07:28 PM

2 cylinders are up at the same time, 2 are down at the same time. Firing order is independent. They fire 1 3 4 2.

So while 1 is on the power stroke, 4 is on the intake stroke.

I need to know how many pulses BEFORE the missing teeth the injector fires. That will tell us when it happens in the intake stroke in degrees.

I also need to know if the injector starts firing EARLIER in the intake stroke as load is added to the motor or if start of firing is always the same number of crank teeth before the gap.

I would also like to know when the injection ends under maximum load. Does the injection end BEFORE the compression stroke or does it carry on through the compression stroke? Measure the falling edge of the injection command with respect to the missing tooth. The injection command should get wider and wider as load is added.

PM me your number and I can chat with you about it :)

djuosnteisn 10-10-2009 07:34 PM

Quote:

Originally Posted by Lex (Post 333497)
2 cylinders are up at the same time, 2 are down at the same time. Firing order is independent. They fire 1 3 4 2.

So while 1 is on the power stroke, 4 is on the intake stroke.

I need to know how many pulses BEFORE the missing teeth the injector fires. That will tell us when it happens in the intake stroke in degrees.

I also need to know if the injector starts firing EARLIER in the intake stroke as load is added to the motor or if start of firing is always the same number of crank teeth before the gap.

I would also like to know when the injection ends under maximum load. Does the injection end BEFORE the compression stroke or does it carry on through the compression stroke? Measure the falling edge of the injection command with respect to the missing tooth. The injection command should get wider and wider as load is added.

PM me your number and I can chat with you about it :)

Your def right on the intake strokes, here's a pic super had:
http://i135.photobucket.com/albums/q...1/DSC01046.jpg


tomorrow will be a good day of loading and hopefully a few races. I'll update when i haz mo infoz.

superskaterxes 10-10-2009 07:36 PM

so let me get their straight,

we have uber car wizardz (lex, 06speed6)
super passionate car loverz (me,dj, +otherz)

a bootlegged ass scope, a buncha picts, and some other vidz and pictz and we are figuring out some crazy important shit? where are all the other companies doing this leg work and R&D who actually have dynos and scopes and all kinds of tools at their disposals? and cobb wonders why we wanted ATR before the protuners got it haha. MSF community members FTMFW!!!!

Lex 10-10-2009 07:56 PM

What I can tell from the pictures so far is that the injector fires close to half way through the intake stroke. So between 70-90 degrees after TDC when the piston is moving downwards and pulling in air.

It will be really interesting to see if the injectors move their start time around depending on load and when they stop injecting at maximum load. I don't know if they move into the compression stroke at all or not.

Alright, Sat night and I'm off for the nice.

DJ, awesome work!

djuosnteisn 10-10-2009 08:03 PM

Thanks lex, we'll get-r-figured out.

I'm still really liking the idea of the crank pulse equating to BDC. Any way we can prove this one way or another.

Anyone who built their own motors may know *cough* mark *cough*?

Lex 10-10-2009 08:16 PM

Quote:

Originally Posted by djuosnteisn (Post 333523)
Thanks lex, we'll get-r-figured out.

I'm still really liking the idea of the crank pulse equating to BDC. Any way we can prove this one way or another.

Anyone who built their own motors may know *cough* mark *cough*?

I did figure it out. Look at my post above with the crank wheel. It's from the FSM. The missing teeth are 20 teeth before TDC of cylinder 1.

Since the wheel has 60 teeth. 20 teeth out of 360 degrees = 120 degrees.

So the missing teeth are 120 degrees BEFORE TDC, or 60 degrees AFTER BDC of cyl 1.

http://www.mazdaspeedforum.org/forum/foru...rank-wheel.jpg

06Speed6 10-10-2009 10:12 PM

The apparent double injection opening is actually the injector opening and then closing, its +100v open and then the current reverses and its -100v closed. From the injector designs that I have seen, there isnt a spring sufficient hold the pin valve open or closed - its all electromagnetic. EDIT #2: So there should be 2 injector events per 4 cycles.

Also on any electormagnetic coil there is a certain reaction time that is unavoidable in the design, which may be why we are finding it at weird points in relation to crankshaft degrees. I guess it should also be noted that the coil reaction time is related to the size of the coil and the current used to drive it, the smaller the coil the lower the reaction time and the higher the current the lower the reaction time, and I suppose it should also be noted that the reaction time for a coil is very very fast, but on a highly precise milisecond time scale there could be some delay inherent in the design. EDIT #1: I should also be noted that you will not be able to "see" the reaction time on the scope, but you may be able to see it open ealier than normal because the reation time is hard coded into the ECU or injector driver logic.

I know from my time doing car audio comps that speakers, which are a coil, have apperitions which show on a scope. This is the resistance of the piston to movement or the backwards movement of the piston in relation to the direction it is being driven, or EDIT #3: the movement of the piston in the direction of the drive but after after the drive event has concluded. If you put a speaker on a scope you will immediately notice that there is a return current that is relative to the sent current and this must be dampened by the amplifier (our car has an injector driver which is a voltage amplifier). The amount of dampening provided by the amplifier is in direct relation to its capacitive capacity, and in real world terms, the quality of the wave it produces on a scope. Also in real world terms, any coil can be called a motor, and any motor can be called a generator.

EDIT #4 I guess it should also be noted, before anyone asks, the current generated by the coil has no effect on the injector driver, but it does effect the movement quality of the cycle of the coil.

Lex 10-11-2009 01:17 AM

1 Attachment(s)
This is unfortunately incorrect. The double signals are from the fact that the positive signal lines on inj 1,4 are tied together as are 2,3. There is no specific signal to close injectors, they simple close once the hold period is over.

The negative signal lines are independent on all the injectors.

This is shown in the FSM section attached.

DJ, when measuring injectors, please measure both the signal at the injector and the ECU signal as well.

The injectors are also around a 70V signal, not 100V.



Quote:

Originally Posted by 06Speed6 (Post 333585)
The apparent double injection opening is actually the injector opening and then closing, its +100v open and then the current reverses and its -100v closed. From the injector designs that I have seen, there isnt a spring sufficient hold the pin valve open or closed - its all electromagnetic. EDIT #2: So there should be 2 injector events per 4 cycles.

Also on any electormagnetic coil there is a certain reaction time that is unavoidable in the design, which may be why we are finding it at weird points in relation to crankshaft degrees. I guess it should also be noted that the coil reaction time is related to the size of the coil and the current used to drive it, the smaller the coil the lower the reaction time and the higher the current the lower the reaction time, and I suppose it should also be noted that the reaction time for a coil is very very fast, but on a highly precise milisecond time scale there could be some delay inherent in the design. EDIT #1: I should also be noted that you will not be able to "see" the reaction time on the scope, but you may be able to see it open ealier than normal because the reation time is hard coded into the ECU or injector driver logic.

I know from my time doing car audio comps that speakers, which are a coil, have apperitions which show on a scope. This is the resistance of the piston to movement or the backwards movement of the piston in relation to the direction it is being driven, or EDIT #3: the movement of the piston in the direction of the drive but after after the drive event has concluded. If you put a speaker on a scope you will immediately notice that there is a return current that is relative to the sent current and this must be dampened by the amplifier (our car has an injector driver which is a voltage amplifier). The amount of dampening provided by the amplifier is in direct relation to its capacitive capacity, and in real world terms, the quality of the wave it produces on a scope. Also in real world terms, any coil can be called a motor, and any motor can be called a generator.

EDIT #4 I guess it should also be noted, before anyone asks, the current generated by the coil has no effect on the injector driver, but it does effect the movement quality of the cycle of the coil.


RayRayBauder 10-11-2009 08:11 AM

holy shit. i just read all of the OP, and the majority of that went over my head. then i continued reading the other posts and the majority of those went over my head. from what little i understand it seems like you guys are doing good work. mad props for trying to figure this shit out.

djuosnteisn 10-11-2009 08:43 AM

Quote:

Originally Posted by Lex (Post 333644)
This is unfortunately incorrect. The double signals are from the fact that the positive signal lines on inj 1,4 are tied together as are 2,3. There is no specific signal to close injectors, they simple close once the hold period is over.

DJ, when measuring injectors, please measure both the signal at the injector and the ECU signal as well.

Great info here lex,
*edit to shrink this ginormous pic*
http://i359.photobucket.com/albums/o...Injsignals.jpg

Here's the scope shot when i was trying (and failing) to match ecu to injector:
http://i359.photobucket.com/albums/o...n/_MG_9459.jpg


My scope shot captures both injector events inject (-) & inject (+) in one screen cause i was triggering on the injector trace. You can clearly see both waveforms there.

Also note on the pic you attached lex, the bottom screen shot is at 400us/div and the top one is at 20ms/div, so if you opened up the bottom screen shot, it'd have a similar periodicity to the top one.


The whole fact that there is a control plus and a control minus control lines means there probably is an opening and closing event. And the fact that the opening events are shared by sets of injectors explains why i was easily fooled during my ecu mapping.



Lex, why do i have to monitor the injector directly? It ads quite a bit of headache to my setup, cause i'll have to run a wire from the engine bay. If we know that the ecu control signal shows the injection event well enough, won't that work?

Basically if they triggered their plots like mine, would probably look like this, lol
http://i359.photobucket.com/albums/o...njsignals2.jpg

Here's two more count pictures for spark and the crank notch. This is a single trace, zoomed in so that you can see the left side in one pic, and the right side in the other. Only way to really get the resolution to count the peaks. I put a note in the pic with my spark advance.
http://i359.photobucket.com/albums/o...otchcount1.jpg

http://i359.photobucket.com/albums/o...otchcount2.jpg

Also here's a video showing the control signal varying with fuel injection amount. I'd prefer to just have to log this control signal from the ecu cause then i wouldn't have to run a cable from the engine bay. My car is starting to look like a fucking time machine, lol. If anyone thinks this is not adequate, lemme know and i'll stop bitching and do what needs to be done.

Once i get some decent logs, and we settle on exactly where TDC is in the crank signal, we can start talking about what implications this data has on our platform. From initial looks at it, it looks like the spray starts pretty close to TDC on the intake stroke. So maybe lenny's cobalt buddies were right in saying over lap can rob power by pushing fuel out the exhaust. I'm not sure, but we'll find out.

Lex 10-11-2009 11:12 AM

The spark actually happens at the end of the pink trace (falling edge). When the signal is high, it is charging the coil. When the edge falls, the spark happens. I counted about 18 crank pulses from the missing tooth to the end of the spark event in this picture. Every crank pulse is 6 degrees. So 6*18 = 108 degrees. Since spark happens at 10 degrees before TDC, that means it is 108+10 = around 118 degrees from the missing tooth to TDC. Which is correct. Nice capture!

http://i359.photobucket.com/albums/o...otchcount1.jpg

As for logging the injectors, nice video! That shows me the command from the ECU is enough to look at.

I can't tell from the video if the ECU moves WHEN it injects around. As you see, when you rev it, the crank pulses become faster. So this might be tricky, but keeping the missing tooth on the screen will give us the reference needed (as long as we can still count teeth). Are you logging on the scope itself or taking a video of it? If taking a video, vary load very slowly with a passenger and change the timescale as RPM and load increases so that you can still see the missing tooth.

Great stuff so far! We're getting somewhere!

Darksun280 10-11-2009 11:17 AM

Quote:

Originally Posted by Lex (Post 333418)
NICE! The crank signal is correct. The spark signal is correct as well.

The gap in the crank signal is the missing tooth. I think there are 32 crank teeth in total with 2 missing. Crank your time scale a little bit and you will the many missing teeth.

*The more you know*

MS6's and Ms3's tooth count are different when doing timing.













*This knowledge nugget has been brought to you by Darskun280 inc.*

Lex 10-11-2009 11:28 AM

1 Attachment(s)
Here's the image marked up

Lex 10-11-2009 11:30 AM

Quote:

Originally Posted by Darksun280 (Post 333771)
*The more you know*

MS6's and Ms3's tooth count are different

*This knowledge nugget has been brought to you by Darskun280 inc.*

From the data I have seen, the above is correct. 60 tooth wheel with 2 missing. the missing teeth are 20 teeth before TDC.

EDIT: The regular Mazda 3 duratec indeed has different crank wheels.

djuosnteisn 10-11-2009 12:18 PM

Quote:

Originally Posted by Lex (Post 333767)
I can't tell from the video if the ECU moves WHEN it injects around. As you see, when you rev it, the crank pulses become faster. So this might be tricky, but keeping the missing tooth on the screen will give us the reference needed (as long as we can still count teeth). Are you logging on the scope itself or taking a video of it? If taking a video, vary load very slowly with a passenger and change the timescale as RPM and load increases so that you can still see the missing tooth.

Great stuff so far! We're getting somewhere!

Adam (my video bitch) is on his way over right now. all i was trying to do in that vid was show you how the ecu increases the injection length. We'll be taking lot's of video, with injection timing (not just amount, but also relative to TDC & spark) as the main criteria. We'll go do different loads & pulls and adam knows how to work the scope pretty well now, so he can start and stop it and zoom in and stuff so we can count cranks.

Also we'll try to get some shots with the dash hawk present so we'll know what timing advance the ecu was running on the spark, adn if that moves the injector timing as well (i've had a suspicion that spark advance affects the injection event) so we'll know for sure later today.


Thanks for everyone's help on this shit.

JumpingJackson 10-11-2009 02:54 PM

This is *very* interesting!

djuosnteisn 10-11-2009 04:07 PM

Data is here, uploading to photobucket, taking quite a while, but i'll post it as it's up. Some interesting stuff, i think people here will really really like it :) !

psychophyr 10-11-2009 04:09 PM

You guys are about to blow some shit wide open. Good work!!!

Deadman 10-11-2009 04:12 PM

*SUSPENSE*

djuosnteisn 10-11-2009 04:13 PM

*adds to suspense*

taking for fucking ever to upload.

SSinstaller 10-11-2009 04:34 PM

This is great! May be we'll finally get some concrete info, instead of all the conjecture..

djuosnteisn 10-11-2009 04:43 PM

So here are some vids, triggering off the rising edge of the fuel injection event (when injection has stopped). The scope was set this way from when i used it last, and i didn't think to change to falling edge for beginning of injection event until later (cause i wasn't the one looking at the scope, i was the one with tight sphinctor going 140 trying not to kill us, lol).

Here's a 3rd-4th vid with a datalog to match
http://i359.photobucket.com/albums/o...sn/3-4log1.jpg
Boost curve on teh 3rd gear portion looks a lil fucked up, but that's cause i rolled into it wierd, the rest of it is legit and a good representative of the boost & afr's and slight creep i experienced.

Here is a 2-3-4th, it looks pretty good and filmed well:

Here is a 2-3-barely 4th. You can see how the injector spray will overlap with the spark event slightly. I think this happens at teh shift point.

Here's 2 vids of 2-3-4 i think after i started triggering on the falling edge (injector beginning). It helps kinda with seeing the injector event relative to crank signal. There is glare, but you can see the cursor in the upper right hand corner, this is when the injector opens.

Some things to note:
- The injection event is taking up ALOT (read ALOT) of the intake stroke. And you can see how close it gets to the spark event (which when at wot is usually no more than 12-13 degrees BTDC)
- The injector appears to start spraying quite near TDC on the intake stroke. Adam and i did a pull, and stopped the scope at 4500rpms, and counted 24 pulses (to the left of when the injector starts) between the pulse (missing tooth) of the crank sensor. We did the same thing again and stopped the scope at like 6300rpm, and only counted 21 pulses..... so to summerize
...4500 rpm: 24 pulses between missing tooth and injector opening
...6300 rpm: 21 pulses between missing tooth and injector opening

That's about 18 degrees or so moved to the left in the higher rpms. So for the most part, the fuel injector will just stay open longer (closer towards the spark event, as evidenced in the videos), but maybe if it has to, it will move to the left (closer to TDC of intake stroke) a bit, not much, just a bit.

- The time scale during all these videos does NOT change, so as the crank signal and spark event start to squeeze in (cause rpms are increasing) the amount of fuel injected is going to be pretty much constant. We are looking at a single cylinder event, so the amount of fuel injected is pretty much constant across the rpm range (boost creep probably offsets some of my ve lol, keeping my torque decent ish, not sure). My afr's stay right in mid 11's throughout wot.


Have at it guys. To me... This looks like at my power levels (3071, dynoed at 355 sae corrected, so not as powerful as many people at sea level, but definitely not weak) i'm already looking at a very little room for further fueling. But maybe i'm missing some stuff here.

I'll still leave everything hooked up for another week and i'll drive my jeep, but i have to bring the scope back to work during the day lol. I think the vids give us exactly what we need, so not sure what else anyone would want me to film, but just cause it's alot of setup time, i'll leave it hooked up.

Darksun280 10-11-2009 04:47 PM

to some up what you said am i right that when you command more fuel to meet command it sprays longer so theres a chance its overlapping injection time into the exhaust stroke?


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