Scope view of Cummins CR injection events. Pilot is always active.

[Joesixpack]

Been studying up the electrical signals before I go to a stand alone ecu.

The tune I had loaded was good old faithful Smarty TNT/r 5 tq3 tm 3.

So for a few observations........the third event.....IS NOT melting pistons, because it isn't active under full load, ONLY light throttle and below about 2200 rpm.

The pilot event is always active.....lots have said that it turns off at such and such rpm, well I haven't scoped the stock tune yet, but its always on with this tune, and really doubt its different with the stock tune.

In the scoped views the red fill directly after the high voltage peak is the "Fuel" as you apply the throttle this full bar's accross the main event and for #5 that is as much duration as it gives it.

My guess #9 slides it farther across, and will scope that later.




3333 rpm pilot still active.

4166 rpm and the pilot event is still there.

1470 rpm full load.....Smarty 5 tq3 timing 3

1923 rpm reference to the 1470 pull, notice timing change to second event.

Main event 2.44 ms Smarty 5 tq3 timing 3 1470 rpm

 

[joefarmer]

I can't find where it was posted, but when Marco was over here testing they figured out the 3rd event didn't seem to be detrimental.

 

[JasonCzerak]

As I've gone to larger injectors, you can really hear the tone change over rpm. I figured it had to be the event could of changed.

I recall that macro turned off the event and lost like 100hp. Maybe the events merge into a big long one?

Nice scoping.

 

[Joesixpack]

As I've gone to larger injectors, you can really hear the tone change over rpm. I figured it had to be the event could of changed.

I recall that macro turned off the event and lost like 100hp. Maybe the events merge into a big long one?

Nice scoping.

Haven't figured out to show live data off the scope on here, but the third event is only at light Rpm and at ~2200 rpm is gone.

It does not merge into the main event, just totally switched off.

I remember that too when someone said that they lost 100hp when they turned it off....which is BS considering it`s not there anyways.


Of interest is at 4000rpm you can see the pilot high voltage spike is full voltage, however the main injection high voltage peak has dropped by quite a bit.

I think we would be better served if the pilot was turned off, and focus on the main event at high rpm.

Don't know much about efi live but pretty sure they turn pilot off at 2500 or so.

 

[jlibert]

Probably the most informative post I've read in a long time. Thanks.

Now my fuel mileage is starting to make sense. The best mileage I've ever seen has been when i'm going 80+ (over 2200 rpm...)

Thanks again,

jp

 

[wpeschel]

Probably the most informative post I've read in a long time. Thanks.

Now my fuel mileage is starting to make sense. The best mileage I've ever seen has been when i'm going 80+ (over 2200 rpm...)

Thanks again,

jp

x2 op:op:op: I'm gonna enjoy some pop corn..

 

[94 12valve]

x2 op:op:op: I'm gonna enjoy some pop corn..

X2, I would like to hear more on this

 

[GOT-Torque]

Thanks for sharing your info... :clap:

 

[SledPuller21]

Haven't figured out to show live data off the scope on here, but the third event is only at light Rpm and at ~2200 rpm is gone.

It does not merge into the main event, just totally switched off.

I remember that too when someone said that they lost 100hp when they turned it off....which is BS considering it`s not there anyways.


Of interest is at 4000rpm you can see the pilot high voltage spike is full voltage, however the main injection high voltage peak has dropped by quite a bit.

I think we would be better served if the pilot was turned off, and focus on the main event at high rpm.

Don't know much about efi live but pretty sure they turn pilot off at 2500 or so.

Awesome info. It's a shame the companies that write these programs can't share or even have knowledge to what you've just shared.:clap:

 

[XLR8R]

Hope this will put another nail in the "3rd event-caused melted CR pistons" coffin... should've been settled 2 years ago. :banghead:

 

[doug60]

Stand alone is looking better & better.
thanks for shareing,
doug

 

[Big Swole]

That JoeSix Cat has some MAD skill's , eh??

Nice man!!


op:

 

[Kronic_187]

the most kickass avatar i've ever seen swole

 

[Big Swole]

the most kickass avatar i've ever seen swole

I freakin Love it! I just got the email and couldn't figure how to save the pic so I just a pic of the screen with my iphone...lol


He's TOTALLY blaming everthing on Bush!!! He's a punk!!



Sorry for the derail!!!

 

[Begle1]

Could you share your interpretation of the graphs a bit better to help get me on the same page?

3333 rpm pilot still active.

What wire is the A lead going to? What is the voltage scale on A channel?

1923 rpm reference to the 1470 pull, notice timing change to second event.

How are you comparing timing? Wouldn't you want to trigger off of the voltage spike on A channel and then count how many engine position pulses you are from the missing tooth?

Is it that there are 59 pulses and the rising edge after the missing pulse triggers #1 TDC?

1470 rpm full load.....Smarty 5 tq3 timing 3

So the first spike is the pilot injection, and that is occurring right at TDC, and then the main event is several degrees after TDC?


Are you doing scoping with the engine under a load or in neutral? Is the programming smart enough to detect load and change fueling accordingly?

 

[BigDamnCummins]

op: and a lil :Cheer:

 

[Joesixpack]

Could you share your interpretation of the graphs a bit better to help get me on the same page?



What wire is the A lead going to? What is the voltage scale on A channel?

The voltage scale on the A channel is right on the screen 20V/div. I have a TST on my truck so I just probed the injector harness for simplicity.

How are you comparing timing? Wouldn't you want to trigger off of the voltage spike on A channel and then count how many engine position pulses you are from the missing tooth?

I'll have some more shots later.......wiring both waste gates full open so I can flog it longer at a sane power level.


Again the information is on the screen, you can see I'm edge triggering waveform A.

Yes you could calculate actual timing, but you would need to know what tooth aligns with TDC for the cylinder you are probing.

When I made the reference to timing, I wasn't making a direct comparison to crankshaft angle and injector opening, rather the delay between the pilot injection and main injection.

As you can see as the RPM goes up the delay is less and less, to the point at 4000 RPM they are almost combined, and makes no sense to me to even have a pilot then. Why not save the electrical energy for the main pulse.

Is it that there are 59 pulses and the rising edge after the missing pulse triggers #1 TDC?

Our Crankshaft tone wheels are the Bosch 60-2. 60 teeth, of which 2 are blanks. Again to check actual timing, you just need to find which tooth lines up with TDC for that cylinder.

So the first spike is the pilot injection, and that is occurring right at TDC, and then the main event is several degrees after TDC?

Yes the first spike is the pilot injection, with the next being the main event. (I didn't show any shots with all three but will later)

Again, can't read the actual timing from this, until you know what tooth lines up with TDC for the injector that is being probed.

Are you doing scoping with the engine under a load or in neutral? Is the programming smart enough to detect load and change fueling accordingly?

The high rpm shots are no load, and the lower rpm shots are under load. (The blocks of red PWM) for current control of battery voltage on the main shot.

The Ecu's have a governor just like a mechanical pump, just with calculations determine load and adjust fuel accordingly.

 

[5150ram]

I did some testing on a 07 the other day and I used 2 channels, one for bank one the other on bank two. The problem I had was one bank was much higher in voltage than the other. Is that normal or is the computer jacked up. Thanks Chris.

 

[Toolman]

This is cool stuff, what are you using to scope it? It't too bad we couldn't have seen something like this a few years ago if would could have gotten someone to change it we might have saved a quite a few engines.

 

[onetun]

Wouldn't you know it

Chris I take it you are on the road again/ intense info, will call you in a few.