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Discussion Starter · #1 ·
I've learned alot about these systems since installing EFILive in the LLY (well, the onboard PC anyway). Just thought I'd share a few thoughts.

1. The main power setting comes from a desired injection quantity (per cycle) expressed in cubic millimeters. There is a table in the control that tells the injectors how long to stay open for a desired fuel amount, at a given fuel rail pressure.

My aftermarket tuner changes these tables in certain regions of fuel pressure and desired qantity. That means more fuel will flow, and the computer won't know. E.g. it wants 50 mm3 and gets 60 mm3, but it thinks its going to be getting 50, and that's used in all other calculations...

So, if the transmission looks at fuel quantity for info on how hard to hold the plates, it'll use a wrong number. If the engine estimates torque from fuel injection flow, for use by the trans, that'll be wrong too. That explains why the trans has a conniption when I change the tune (using this method).

It's logical that if you wanted to calculate fuel mileage, you look at the injection amount per cycle. RPM/4 tells you how many cycles there are per minute. From that you can get fuel flow. From the VSS, you can calculate mileage. Of course, if you're using 50 in the calcs, and 60 is really flowing, then the mileage calc will be wrong, in favor of higher mileage calculated.

2. Question, in the boost tables. There is a vane position minimum (max opening). No problem. That's the most it will open as a function of RPM and fueling. There's a Maximum vane position table too...the most it will close as a function on RPM and fueling. But, what is the table "Turbo Vane Target Position"? I thought it was varying vane position in order to reach a target boost pressure? Like, it would stay at the maximum setting (most closed), until boost comes up, then opens a bit to hold it at the desired boost value. What gives? Or is the target where it stays, until modulating, bound by the min and max? I'm going to have to add vane pos to my dashboard and watch it as I drive to see what it's up to.

In the idle range of RPM and fueling, the max and min are both 58%. I guess that means it's locked at 58% at idle.

3. MAF. There is a table of expected airflow vs. RPM and fueling. But there is a temperature value of 150C above which the collant must be in order to test airflow using this table. That basically means the table is not used. So, since the MAF appears nowhere else in the fueling calcs, the only use of the MAF sensor is for testing the EGR? OF course, you can look at it move around, but it does nothing.

4. Fully disabling EGR is easy. There are min and max RPM values for enabling EGR. Stock they are 200 min and 3500 max. I changed them to 4000 min and 4100 max. No more EGR. I also disabled the diagnostic test, So no more trouble code.

5. The speed limiter is obvious. Between 177 and 193 km/hr, it cuts off fueling. Change the value at 193 to 120 mm3, and no more speed limiter.

6. Interesting enough, there is little modification of fueling, as a function of throttle and RPM. There is a table, and the resulting value is modified if in engine protection mode, or overheating, but other than that, that value gets injected. The fuel pressure, and timing vary with ECT, BARO, fuel temp, etc...but not the fueling rate itself. I was surprised anyway.

7. Is the value in injection timing, the start of the pilot, with the main injection coming "Injection timing after pilot" later? For the base timing, negative is after TDC, and positive is before TDC, right?

Timing appears very conservative. At idle, the base timing is actually after TDC. It also looks like the timing is almost always after TDC for the main. This has to be for NOX, and means there's lots of room for improvement in terms of economy.


Lots to learn. Nice job on the program, BTW.
 

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Discussion Starter · #2 ·
Correction:

In stock tune, while highway driving, the main timing does vary from 0 to about 5 degrees. Not the optimal 10, but it is BTDC.

The pilot timing goes as early as 20 deg.

It looks like the base timing is the timing for the main injection, and the "main timing after pilot" value is used calculate when to set off the pilot injection.

Can anyone confirm?
 

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Correction:

In stock tune, while highway driving, the main timing does vary from 0 to about 5 degrees. Not the optimal 10, but it is BTDC.

The pilot timing goes as early as 20 deg.

It looks like the base timing is the timing for the main injection, and the "main timing after pilot" value is used calculate when to set off the pilot injection.

Can anyone confirm?
That's my understanding also.
 

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Discussion Starter · #4 ·
Another question.

When driving with the engine cold, the pilot injection goes as high as 5 mm3. In the pilot injection table, it's never near 5 in any of the cells.

Is there a cold pilot injection table, not identified?

Once warm, the quantity does match the table.
 

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When below 72C there is a Fuel Pressuer multiplier based on ECT and when the BARO is below 82kPa there is another multiplier. Otherwise as far as I can tell the only other thing is injection timing but I don't see how that could change the readings. Not sure if this really helps or not.
 

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Discussion Starter · #6 ·
My understanding is this:

The fueling tables deceide how much fuel to inject (main), based on throttle and RPM. Then the pilot fueling gets determined based on the main injection, according to the pilot fueling table.

Once both are now determined, the fuel pressure desired gets looked up. Then the pulse times (pilot and main) get looked up according to fuel pressure and desired fuel quantity.

Even if the pressure is varied, i don't see how 5 mm3 of pilot fuel can ever be the desired amount based on the one pilot injection table (which has no cells over 2 mm3).

I'm thinking there are A,B,C pilot injection tables for different ECT ranges like there are elsewhere.

Once warmed up, I can watch it follow the tables, while driving. It does follow the pilot table, just not when cold.

Just trying to learn how it works, before I start messing.
 

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My understanding is this:

The fueling tables deceide how much fuel to inject (main), based on throttle and RPM. Then the pilot fueling gets determined based on the main injection, according to the pilot fueling table.

Once both are now determined, the fuel pressure desired gets looked up. Then the pulse times (pilot and main) get looked up according to fuel pressure and desired fuel quantity.

Even if the pressure is varied, i don't see how 5 mm3 of pilot fuel can ever be the desired amount based on the one pilot injection table (which has no cells over 2 mm3).

I'm thinking there are A,B,C pilot injection tables for different ECT ranges like there are elsewhere.

Once warmed up, I can watch it follow the tables, while driving. It does follow the pilot table, just not when cold.

Just trying to learn how it works, before I start messing.
I think you might just be onto something here. Do you have an IAT and/or an ECT reading when the Pilot changes?
 

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Discussion Starter · #8 ·
I dont think its based on IAT. My IAT doesn't change much from startup to freewat running (at least not this time of year).

I'll try to watch for the ECT when I notice a change in the pilot quantity. I've been running EFILive Scan as I drive, watching what it's up to on the onboard PC. I have a custon dashboard with more parameters including both timings and injection quantities.
 

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Another question.

When driving with the engine cold, the pilot injection goes as high as 5 mm3. In the pilot injection table, it's never near 5 in any of the cells.

Is there a cold pilot injection table, not identified?

Once warm, the quantity does match the table.
Good observation!.
There is a table missing in the editor that is another 'adder' to the base pilot table with values as high as 8mm3 when really cold to 0mm3 when hot. That will be in the next update.

Cheers,
Ross
 

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Discussion Starter · #11 ·
Good observation!.
There is a table missing in the editor that is another 'adder' to the base pilot table with values as high as 8mm3 when really cold to 0mm3 when hot. That will be in the next update.

Cheers,
Ross
Ok, knew something had to be modifying the base pilot table. Thanks.

In answer to the last question, based on watching the pilot injection (and the road), it looks like it goes to the base table only once ECT has warmed up past about 55C.
 

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Discussion Starter · #13 ·
Thanks.
 

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Ok I have been reading all about this EFILive. I am interested in it, but after reading this thread your scaring the hell out of me. I am a fairly smart man but is this something the average diesel fan would benifit from?
 

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If I can do it anyone can. Just do small changes and one change at a time until you start to get familiar with it. I do lots of logging as well.
 

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Discussion Starter · #16 ·
Ok I have been reading all about this EFILive. I am interested in it, but after reading this thread your scaring the hell out of me. I am a fairly smart man but is this something the average diesel fan would benifit from?
This program does give unfettered access to the innermost workings of your ECU...and in a user friendly way.

That said, you are messing with the brain of your engine. You can do stuff that can hurt it....and no box will pop up asking if you're sure you want to change fueling to 200 mm3!

It's a reason to be careful, not scared.
 

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Changing the fueling to 200 mm3 wouldn't hurt anything.;)
This program does give unfettered access to the innermost workings of your ECU...and in a user friendly way.

That said, you are messing with the brain of your engine. You can do stuff that can hurt it....and no box will pop up asking if you're sure you want to change fueling to 200 mm3!

It's a reason to be careful, not scared.
 

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This program does give unfettered access to the innermost workings of your ECU...and in a user friendly way.

That said, you are messing with the brain of your engine. You can do stuff that can hurt it....and no box will pop up asking if you're sure you want to change fueling to 200 mm3!

It's a reason to be careful, not scared.
Well thank for the help, you are right careful, not scared is ususally where I start.. I really like the Diag. feature. Since I don't know what mm3 is I probably wouldn't change it until I researched it to death...
 
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