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Fuel Injector Sizing

Closed loop bias

No, any suggestions as to what to change them to?
 



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just guessing

With your smaller injectors the test ran with a load of .28, MAF count of 275 and TP of 236. Since you've probably changed your MTF to tune your AFR I don't know what the comparable load would be. You might try changing the Closed Loop Bias entries for load </= .3 and rpm </= 2000 to +.005 and see if that makes a difference.
 






injectors

I will do a datalog of the OBD O2 monitors again and see where the load is and then I will give it a try.
 






Fuel Injectors

State inspection is coming up next year and I am tired of knowing that my fuel control is not optimum.

I just ordered these injectors to try out.
0280158279
47lb injectors @ 39.15 psi
They would be 52 @ 43.5 psi
The ford racing part number is M-9593-LU47
There is a value file in AdvantageIII for these injectors.
I ordered them off eBay and they come with connector adaptors that I may or may not use.
 

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easier to tune

Those should be much easier to tune. My opinion is the optimum injector rating is just slightly greater than the max needed for normal fuel pressure. If improvements are made that increase airflow the fuel pressure can be increased to compensate. The only reason I let James convince me to purchase my Deka 60s is because they were advertised to have very good low duty cycle control. One problem with small displacement, high power engines is the wide range of injector flow needed to maintain the correct AFR. My 4.6L V8 will have a 14% lower flow need than my 4.0L V6 for equivalent power per displacement.
4.6/8 = .575 4.0/6 = .667 .575/.667 = .86
 






Injectors

I will post the results when ever I get them and put them in. I am hoping this happens during Christmas break. We will see.

I have to mention some other thoughts.
Although the minimum pulsewidth is important to look at, there is a question that needs to be thought about. How much fuel flow will you have at that minimum pulse width?
The 60lb Deka is a bigger injector and it has a larger minimum repeatable pulse width.
The 47lb Bosch is a smaller injector and has a smaller minimum repeatable pulse width. So in theory it might work.

Now I was also looking at Injector Dynamics ID725. They are around 68 lb injectors. They have a smaller minimum repeatable pulsewidth lower than the Deka 60's. This might be a good injector to go to if the Bosch's are to small for further/future modifications.
They are around $700.00 for 6 of them, much higher than the 238.00 I just paid for 6 of the Bosch 47's, but price isn't what's most important. Having them work is the most important thing and I will have to test them out to find out.

With the price so high for ID's I had to email them and ask if they would work in my Explorer and pass the Rapid Response O2 sensor monitor test. I figured from researching them, that they may be able to compute what amount of fuel flow in liters that I would need and see if the ID725's would be able to achieve that. They seem that smart. I sent them an email but have not heard back from them so I went ahead and pulled the trigger on the Bosch ones for now.

Edit: I did get a response from Injector Dynamics, they say that they most likely will work. The ID725's have been used in several applications that required the vehicles pass emissions and still have a large amount of fuel flow for high horse power. They also have been used in motorcycles. lol.
I am hoping to try them out sometime next year.
 






New 47lb Injectors Installed

I installed my 47lb injectors the other day. Before putting it all back together I test fitted a Ford Racing throttlebody and made a bracket for it. It was raining and I hate bringing my truck out in the rain so I didn't mind not being able to start it and check the new injectors' operation right away.
It did stop raining for a few hours yesterday and today so I could get some testing done. I changed the injector data in my tune with a value file. One click and all the data was changed. The value file was one of the reasons I went with these injectors.
Once getting the vehicle up to operating range I did a quick step test up to about 3,000 rpms. I had to change the Maf transfer function about 25-30%. I took the amount of change to the highest MAF count at 3,000 and carried it to the top of the MAF transfer function table as a safety precaution to avoid a lean mixture on the first WOT run I would perform later. The MAF transfer function was now close enough to do further testing. It is not perfect, I will go back and work on it some more later.

So my reason for changing these injectors was being able to pass inspection and having the rapid response O2 sensor monitor test running and passing. This would also mean having better air/fuel mixture control. I got to datalogging and was pleased to see that the monitor test would run and pass now. Screen shots in next post.
 






OBD2 Monitors Passing

Note: I am using Live Link 6.5 for this since it worked 2 years ago when I first encountered a problem after installing 60lb injectors.
I may retest with Live Link Gen2 later. I have found that some "pids" just don't work in Gen2. END NOTE.

There are two pids I found useful in relation to OBD2 monitors. One is OBDII TS which stands for OBD2 monitors completed(ran).
The other is OBD2 ST. I don't know what that stands for but it has something to do with the O2 monitors I assume.

The yellow circle in the first picture below shows that when the PCM's memory was cleared that the monitors completed "pid" shows 0 meaning no monitor test has run. The OBD2 TS reads 1, I don't know what that means.

The second picture shows the yellow circle on the first step. That step reads 16 which means the "closed loop fuel test" ran. That test checks STFT and LTFT to make sure they are not too far away from 0%. The actual specs for the monitor test are:
Lean malfunction: LTFT > 25%, STFT > 5%
Rich malfunction: LTFT < 25%, STFT < 10%
The vehicle would have to be running really crappy to be that far off.
Another note: If one of these monitors fails it should set a code and if it happens two times within two drive cycles the check engine light should come on. My truck passed that test even with it not being completely tuned, no problems so far. The next post I will show how I know that 16 is the closed loop fuel test.
 

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Binary to Decimal OBD2 Monitors

OK, this stuff gets deep. I take no credit for this information as I found this table on SCT's forum. I did not understand it at first but then I found an online Decimal to Binary converter and played with the numbers and my truck with an X3 and a cheap code scanner that reads readiness(OBD2) monitors. With out the online converter I would have been lost because I dont know how to convert Binary to Decimal without it.

SCT shows the decimal numer in Live Link.
The monitors are listed by Binary, see how the 1 is in a different posistion to designate each test.

____________________________________Binary = Decimal
bit 7: Misfire Monitor Test _____________1000 0000 = 128
bit 6: EGR Test______________________0100 0000 = 64
bit 5: HEGO Test ____________________0010 0000 = 32
bit 4: Closed Loop Fuel Test ___________0001 0000 = 16
bit 3: Secondary Air __________________0000 1000 = 8
bit 2: Purge Test ____________________0000 0100 = 4
bit 1: Comprehensive Component Test ___0000 0010 = 2
bit 0: CAT Test ______________________0000 0001 = 1

Decimal Total 255
Minus Secondary Air would be = 247 (255-8=247)

These monitors can run in different orders so the totals can come out to different numbers along the way, but.... they will or should eventually equal the total of all the systems that the vehicle came with, when all the monitors have run.
For instance: My Explorer does not have secondary air, but it has everything else so the total would be 247.
If I turn off the EGR in my tune the total would only be 183.
If I drive all around with that same tune and all the monitors run except the Purge Test(Evap), then I would have 179.

In theory if you set your "OBD test switch" to 18 all monitors will be off except Closed loop fuel(16) and Comprehensive Component Test(2). You would still be able to have codes set for these systems and your PCM would be freed up from doing extra work so it could process other things a little faster if needed.

My "OBD test switch" is listed under OBDII, Chronometric, Scalar, OBDii Test Switch
There is also an OBDII MIL switch which just turns off the PCM's ability to turn on the check engine light for certain OBD monitors.
 






HEGO Test Running

This third picture shows the OBDII TS pid going from 16 to 48.
What monitor just ran?
48-16 = 32
32 is the decimal number for the HEGO test, the one that did not pass with my 60lb SeimensDeka injectors installed.
Two years ago I stumbled across the other pid named OBD2 ST, see how it went to 4. That did not happen with the 60 lb injectors installed, it would stay at 2 or 3. I compared it to my 4 door explorer which is stock to see how it should go to 4. Then I put some old 30 lb injectors in just to get through inspection. I did not want to have to go through removing the supercharger every 2 years to swap injectors so I decided to try the 47's.
So now I know that the 47lb injectors that I just installed will allow my monitors to run and I should be able to pass inspection with these injectors.

New questions,
Will they be large enough to supply an adequate amount of fuel at WOT?
Does the minimum pulsewidth in the value file work or will it cause clipping of the pulse width? See the next post.
 

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Pulse Width and Duty Cycle

The first picture below shows the pulse width jumping up and down at Idle.
No clipping. That means the Value file data works for min pulse width with these 47lb injectors and these specs work with my 4.0L SOHC.

One last thing to check, what will the injector duty cycle go up to?
My 60lb Seimens Deka injectors went up to about 61%
My stock 4 door explorer went up to about 72%
The new 47 lb injectors.....See picture below.
Step 1: You take the number of injectors and multiply that by "Time Between PIP"
Step 2: Then you take "injector pulsewidth in clock tics" and divide it by the total you got from the first step.
So... 6 X 601 = 3606
3190 / 3606 = .88 or 88% duty cycle.
That is a little higher than I wanted. It works for now, but I need to keep an eye on it. There is no room for increased air/fuel flow. I could turn up fuel pressure. I really want to test out a set of injector Dynamics ID725's now!
Some things to consider.
I had 8 rib pulleys made that grab the belt better, the crank pulley is a little bigger in diameter (0.1 I think) so it may spin the supercharger a little faster. I am now hitting about 850 counts with the 2.7 inch supercharger pulley, I used to be hitting about 815-820 counts. I wont even think about putting the 2.5 on it at this point.
I also need to datalog the truck while going through all the gears instead of just doing a 3rd gear WOT pull. I need to finish tuning it but the weather wont let me.
The truck does seem to run so much smoother now.
 

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Nice going!

Congratulations on not having to swap injectors every two years to pass emissions testing. I'm also glad the minimum pulse width is not a problem. If I understand your post correctly, initially the only think you changed in the current tune was the value file for the injectors. Then you changed the MAF transfer function 25 to 30% for the entire range. Was the AFR lean or rich to prompt the MTF change? If your current max MAD AD COUNTS is 850 and the possible max is 1023 then you can increase your airflow by 20% and not go lean while leaving the fuel pressure as it is.

Thanks for mentioning some pids not working with certain versions of LiveLink. I tired to datalog injector pulse width on my 2003 and it's always zero for both banks. Also, there is no pid to log for time between PIP. I'm using LiveLink Gen-II so maybe I'll have better luck with another version if one will work with my XP.
 






Tune changes

Congratulations on not having to swap injectors every two years to pass emissions testing. I'm also glad the minimum pulse width is not a problem. If I understand your post correctly, initially the only think you changed in the current tune was the value file for the injectors. Then you changed the MAF transfer function 25 to 30% for the entire range. Was the AFR lean or rich to prompt the MTF change? If your current max MAD AD COUNTS is 850 and the possible max is 1023 then you can increase your airflow by 20% and not go lean while leaving the fuel pressure as it is.

Thanks for mentioning some pids not working with certain versions of LiveLink. I tired to datalog injector pulse width on my 2003 and it's always zero for both banks. Also, there is no pid to log for time between PIP. I'm using LiveLink Gen-II so maybe I'll have better luck with another version if one will work with my XP.

Yes initially all I changed was the injector data. Then after starting it I saw it was lean(smaller injectors) and had to adjust the MAF transfer Function.
I also notice that on this tune that I am using with no changes to the engine displacement, that at max the load value was close to 100%. Now it is about 130% which is more realistic but still not correct. Not really concerned about it though, the new train of thought is not to change engine displacement just to get load to read what you think it should be.
The maf numbers mean I wont peg the maf, the injector duty cycle at 88% says I might peg the injectors. LOL I have heard of some running injectors at 95% but I don't feel; safe with that. If I raise fuel pressure then I have to scale the injector values, unless I can find some values already made for 43.3 psi instead of 39.15. Even so, what will that do to duty cycle, probably not much.
What is your 2003's strategy number?
Try Live Link 6.5 to see if that has what you need. The other thing is if there is a lower case blue pid, I found that it has a better chance of working with my truck's PCM. The upper case orange pids don't seem to work much, some do some don't. LOL. Always a work in progress with Gen2 I guess. I wish they would show us how to make our own pids, that feature seems to be in the software, just not instructions. One more thought, sometimes there is a more supported strategy for a vehicle, you could ask SCT or post on the forum if there is a better strategy to use for your 2003. If a mustang strategy would work with your PCM hardware maybe you could switch to that.
 






To Look at Injector Duty Cycle in Excel

I am no expert in Microsoft Excel, and I wont claim to be. I used Google 3 times to figure out how to do 3 things in Excel. Also the names of the pids you record may be different for your strategy.
The names for the top of the columns are just suggestions.
These instructions are crude, they are just an attemp to share something I found interesting while looking at injector duty cycle. I may have missed a step or to along the way.

Copy datalog and save it as another name.(so you dont delete the original by mistake)
Open up the newly named datalog in Excel by double clicking it.
Delete everything except TIME STAMP, INJECTOR PULSEWIDTH IN CLOCK TICS, TP, and TIME BETWEEN PIP's.
In an empty column, click in the top box(just below the column letter) and name it CYLINDERS.
In the box below it type 6 (for 6 cyl) and hit enter.
Then double click the little square(see first picture) at the bottom right in the highlighted box with the 6 in it (that should fill the whole column with 6's).

In the next empty column click in the top box and name it NUMBER.
Click in the box below it and type =
Then click the column letter for the TIME BETWEEN PIPs
Then type the * symbol (multiplication)
Then click the column leter for CYLINDERS
Hit enter
Double click the little square at the bottom right in the highlighted box with the newly calculated number in it. The whole column should now be calculated all the way down.

In the next empty column click in the top box and name it DUTY CYCLE
Click in the box below that and type =
then click on the column letter for INJECTOR PULSEWIDTH IN CLOCK TICS
Then type / (divide symbol)
Then click on the column letter for NUMBER
hit enter
double click the little square at the bottom right in the highlighted box with the newly calculated number in it.
You now have a whole column of calculated Injector duty cycle.
Save the file, when asked about format click yes.

Now you can even open up that datalog in Live Link and view it there with your newly created PID for Injector duty cycle. WOW!
I know there is a way to just take Column A and divide it by D*6. This was just my first attempt.
 

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More experimenting with Excel

Here is another screenshot of Live Link.
I just added one column with the formula to calculate Inj duty cycle.
Pretty cool stuff.
I know there is a way to save this as a datalog configuration file. It should work as long as the "pids" are all in the same place each time. I will experiment with it.
 

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max duty cycle

. . . The maf numbers mean I wont peg the maf, the injector duty cycle at 88% says I might peg the injectors. LOL I have heard of some running injectors at 95% but I don't feel; safe with that. If I raise fuel pressure then I have to scale the injector values, unless I can find some values already made for 43.3 psi instead of 39.15. Even so, what will that do to duty cycle, probably not much.

Good point. I should have realized that was your concern. I think 88% would be fine for your current configuration but you may max out after you add those high flow heads.

What is your 2003's strategy number?
Try Live Link 6.5 to see if that has what you need. The other thing is if there is a lower case blue pid, I found that it has a better chance of working with my truck's PCM. The upper case orange pids don't seem to work much, some do some don't. LOL. Always a work in progress with Gen2 I guess.

I didn't record the strategy number when I tried datalogging and I've only opened the hood once since purchasing the vehicle. I've been transplanting decorative trees and bushes when it isn't raining. I want everything transplanted as soon as possible so the roots can get re-established before spring when above ground growth begins. I think I've tried all of the listed pulsewidths and none work. There must be thousands of pids available in the 2003 strategy but at least two thirds of them are KAM values. There are also a group of pids for electronic throttle control which wasn't implemented until 2004.

I wish they would show us how to make our own pids, that feature seems to be in the software, just not instructions. One more thought, sometimes there is a more supported strategy for a vehicle, you could ask SCT or post on the forum if there is a better strategy to use for your 2003. If a mustang strategy would work with your PCM hardware maybe you could switch to that.

I don't understand. I wasn't aware that any more capabilities are possible than what's provided in the latest versions of XP and LiveLink which is not strategy dependent. I thought that only the calibration constants supported in Advantage III were strategy dependent. I haven't yet requested a license expansion for Advantage III to support the 2003. I hadn't considered reprogramming the PCM for a different strategy such as a Mustang. That would take special equipment that I don't have access to and risk incompatibilities with other modules in the vehicle.
 






I don't understand. I wasn't aware that any more capabilities are possible than what's provided in the latest versions of XP and LiveLink which is not strategy dependent. I thought that only the calibration constants supported in Advantage III were strategy dependent. I haven't yet requested a license expansion for Advantage III to support the 2003. I hadn't considered reprogramming the PCM for a different strategy such as a Mustang. That would take special equipment that I don't have access to and risk incompatibilities with other modules in the vehicle.

I may have been combining two different thoughts. One was that I saw on SCT's forum where someone suggested to use a different strategy, it was not from a different vehicle though, just a newer strategy I guess.

The other thought was how the newer cars worked better with Live Link gen2 right away but with my strategy some pids did not work that I needed, at least until Live Link Gen2 was updated in about July of this year. They worked on the newer, most used stuff first since that is where the majority of the tuning is being done now I guess.

What is XP in the above statement?

I saw something in one of your posts that showed me what I did not like about Live Link Gen2(that I just couldn't put my finger on). Just the layout. In one of your more recent posts it looked more like Live Link 6.5 with the names of the pids on the left and the graph on the right. When I saw it I thought, that looks better for a screen shot of Gen2. So I finally just now played with the layout settings in LL Gen2. Some simple things just really get by me sometimes.
I got it now though.
 






SCT Power Flash

. . . What is XP in the above statement? . . .

SCT Power Flash X3, serial number starting with XP. I have one for the 2000 Sport and one for the 2003 Centennial. I updated the firmware on the one for the 2003. I'll try the one for the 2000 to see if it makes a difference. I haven't updated my LiveLink II in at least a year. I'm always afraid I'll gain something but also lose something. With my first version I could set a vertical scale at the beginning for one pid and another vertical scale at the end for another pid similar to a dynojet plot of torque and horsepower. Now I have autoscale based on the selected primary pid. Its a real problem with the 2003 that has numerous spikes in the datalog.
 






Add Calculation Pids to Live Link Gen2

Right click anywhere in the Item Name area and select Add New Quick Calculated Item.
Pic 1

When the box opens up Type a name in the box labeled Main Name.
Pic2

Use the drop down menu to select the first pid in your formula and click Add.
Pic3
Note: for Inj Duty cycle for my truck, the formula is Injector Pulsewidth in Clock Tics divided by (number of injectors multiplied by Time Between PIPs).

You should now see the first part of the formula in the box below.
Pic4

Now click the divide symbol
Pic 5

You have to use parentheses in calculations to get the correct order of operations, click the first one here.
Pic6

Next I typed the number of injectors I have and then the multiply symbol.
Pic 7

Then use the drop down menu again, this time it is Time Between Pips. Select it and click Add.
Pic 8

Finally click on the "end parentheses" to finish the equation, and this time clcik the Add at the bottom right. See picture 9.
Picture 10 shows the finished result.
 

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very helpful

The capability is nice and your instructions are very helpful but I can't do it in my version 2.1. When I right click a pid name my only option is to assign it to a gauge which I never use. I guess I'll take a chance and upgrade my LiveLink Gen II.
 






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