typical fuel to wall impact increase for Siemens Deka 80lb injectors

[5.3LS10]

Hey Everyone,

I have been going back and forth the past couple weeks hunting down miscellaneous issues with my swap and have finally gotten to the point I can focus on getting the VE table and tip in sorted out.

Engine is a 2000 4.8L with genIV rods and pistons with 799 heads, LS9 cam, 80lb injectors and a 78/75 turbo.

First thing is I finally settled to use "this" 80lb Siemens Deka data.
https://ls1tech.com/forums/pcm-diagn...ta-sticky.html

The reason why I say "this" data is because it seems like there has been dozens of posts for people asking for the data and I have found at least 5 different injector settings for these injectors. The post above seems to have helped the most so far.

I used 80lb for the IFR because I have my 1:1 regulator set to 43.5 with the vacuum line unhooked.
I also copied over the 0kpa row for Offset vs Volts vs VAC

I put the injector data into my file with my stock VE table and it ran very rich (11-12:1 at idle)

I then removed 20% of fuel from 400-2400 rpm and 15-105 kpa.

Idle seems better now BUT I am experiencing 2 issues;

lean spikes at tip i
as well as initial start up seems to stumble as soon as it is started and then settles about 5 seconds into running.

The post I referenced earlier mentions to "I'd leave the Fuel to Wall Transient stock. But if you notice any lean or rich conditions on throttle tip in, modify to this. The Min Fuel Mg or Transient Min Mg is a pulsewidth adjustment for idle. Do change this."

I did change the min fuel milligrams down to 0.016 from 0.041 which seems to have helped the idle to not be as rich.
I modified the Fuel to wall impact factor by a lot so far and it seems to still have a stumble. I focused on 120* and up and 40-100kpa.

So my question is how far do you normally have to modify these values by? Maybe experience specific to the siemens deka 80lb injectors if it matters.

I have increased the values by about 20% and still having a lean stumble.

Is it normal to have to put it 30-40%? Is the answer just keep increasing fuel in until its happy or is there something else going on that I am overlooking due to my ignorance.

Tip in is not an issue when it is warming up and under around 120* but it is also rather rich in that range.

One thing that I think is throwing me off is I did not get the engine all the way up to temperature first and do all of my testing at the same temp.

Can someone help kick me in the right direction.

tomorrow I will do a series of 4 or 5 tests all at the same temp to see if I can figure this out for sure but I don't want to waste a bunch of time modifying this value to try and make it as a band aid for a bigger issue.

I have also attached some files and data logs I took.

The "injector data from inj sticky" is the stock VE table and stock transient data.
The "updated transient" one has the 20% reductin in the VE table and ~20% increase in

Thanks everyone!

[dmaxs10]

Well I'm no help but I'm putting in 80s with same data hopeing to run it Sunday. Might be able to help later

[5.3LS10]

Well I'm no help but I'm putting in 80s with same data hopeing to run it Sunday. Might be able to help later

I would definitely appreciate that. Unfortunately there is so much incorrect information out there it makes it hard for people to find the actual injector data.

i don't even know if that injector data is correct.

This should be helpful

http://siemensdeka.com/specsheets/FI114992.jpg

[5.3LS10]

I have been looking around for a spreadsheet to convert this calibration data into the tables for HP Tuners.

http://siemensdeka.com/specsheets/FI114992cs.jpg

Can anyone point me in the right direction for this spreadsheet?

I have one for Megasquirt ECUs but that tables are completely different.

[5.3LS10]

Well I got the 80 and 100kpa rows increased more from 130-190 and it has seemed to help the only thing I noticed is that now it has a hard time starting when warm though. Not sure how this would effect it though.

[dmaxs10]

well it ended up being really cold today so I did not get out to the truck. Sorry I will try again later this week I hope

[dmaxs10]

Got mine in and started today. didn't get much run time or any driving but it stumbles and goes lean in throttle tip in. idled good in closed loop and looked lean in open. have you learned anything on this?

[chevyrules2]

I've never posted on here before but I can tell you that the injector offset data is not right.
I used the same data....

[5.3LS10]

When I get home from work I will post my current tune file. I have been driving the vehicle around and once I got my VE table sorted out it really seems to run a LOT better than it did before. I believe earlier I was fighting a messed up VE table more than bad injector data. I do not notice much hesitation or stumbling like I did before.

[5.3LS10]

I've never posted on here before but I can tell you that the injector offset data is not right.
I used the same data....

do you have a 1:1 fuel pressure regulator?
What is your base fuel pressure set at?

Those should both affect the injector offset data depending on how you have it setup.

[chevyrules2]

do you have a 1:1 fuel pressure regulator?
What is your base fuel pressure set at?

Those should both affect the injector offset data depending on how you have it setup.

My current setup is a 2003 p59 4.8l 4l80e Drive by cable 2bar RTT With 58 psi 1:1 pressure regulator.
Yesterday when I talked to Vernon at VS Racing he told me that the injector offset data is not correct.

[dmaxs10]

5.3ls10 that would be great. I was looking at my logs and I notice my timing was way low so that might be my issue. If your using the same data as me, from ls1tech sticky, then it probably is not the inj data.
Chevyrules2. Would you be willing to explain further. I'm assuming he doesn't want it shared but so you know it it's way off?

[5.3LS10]

My current setup is a 2003 p59 4.8l 4l80e Drive by cable 2bar RTT With 58 psi 1:1 pressure regulator.
Yesterday when I talked to Vernon at VS Racing he told me that the injector offset data is not correct.

So what is the correct data? Could in part be because I am using 43psi base pressure.

[5.3LS10]

5.3ls10 that would be great. I was looking at my logs and I notice my timing was way low so that might be my issue. If your using the same data as me, from ls1tech sticky, then it probably is not the inj data.
Chevyrules2. Would you be willing to explain further. I'm assuming he doesn't want it shared but so you know it it's way off?

I have attached my current tune and a datalog of me driving around. Like I said so far it drives pretty good. I am still working on smoothing out the VE table and working on getting the AFR dialed in under boost.

I am going to reach out to a local guy I know that is using 80s and see if he will send me his data.
<EDIT> I added his file "Jason 80# injectors.hpt"

[chevyrules2]

So what is the correct data? Could in part be because I am using 43psi base pressure.

I wish I knew what the right data was but Vernon recommend using the data off of http://sloppymechanics.com/tune-cabinet/ that Matt uses

[5.3LS10]

I wish I knew what the right data was but Vernon recommend using the data off of http://sloppymechanics.com/tune-cabinet/ that Matt uses

I have looked through 3 of his tunes that used the 80lb deka injectors and they seemed to all have slightly different data on them.

Now that I have the truck running stable, and the VE table tuned better I am going to maybe try and swapping in my friend Jason's data and see how it works.

I will try and come up with a spreadsheet that contains all the different data from different sources so I can try and spot similarities.

Maybe after that I will try using the offset data from a couple of Matt's tunes.

[chevyrules2]

I have looked through 3 of his tunes that used the 80lb deka injectors and they seemed to all have slightly different data on them.

Now that I have the truck running stable, and the VE table tuned better I am going to maybe try and swapping in my friend Jason's data and see how it works.

I will try and come up with a spreadsheet that contains all the different data from different sources so I can try and spot similarities.

Maybe after that I will try using the offset data from a couple of Matt's tunes.

I noticed that too.
The way I understand it is if the injector offset data is correct. if your ve right and if you change the ve say 10% your afr would also show a 10% change I hope that makes sense

[5.3LS10]

I noticed that too.
The way I understand it is if the injector offset data is correct. if your ve right and if you change the ve say 10% your afr would also show a 10% change I hope that makes sense

Yes that is how it was explained to me too. If you have a large variation then you know the offset is incorrect.

I am going to play around on Saturday and try some of Matt's data as well as my friend Jason's data and see where I end up.

[dmaxs10]

That's funny I have seen people say that his tunes a scaled because of wrong data but they seem to work.
So say you change VE 10% and your afr changes 15% would you remove 5% from injector offset re tune then retest?
Thanks 5.3ls10 I will look at it tomaorw.

[cobaltssoverbooster]

short answer is yes thats how you interpret the error feedback.

yes you can tune the offsets this way. ive done it a few times against my own recommendations when running unknown injectors with no readily available data on 1:1 regulator systems.
i measure the injector flow of one injector in cc at the desired rail pressure. this gives you cc/seconds. you can then convert this data to cc/min or lb/hr and enter this into the base flow IFR chart.
testing the IFR rate you add 10 % to a tuned in ve table. if the error reports back -15% then you need to remove some trim from the offset table. basically the multiplier is adding too much to the base flow and causing an over-fuel event.
same but in reverse for going -5% after adding 10% fuel to base.

occasionally i got a set that doesnt want to go along with this method and i apply a technique thats probably not going to make people happy but it does work fairly well as a last resort when sending injectors out for flow testing isnt an option.
set the voltage modifier to 0 from 13v to max volt. then upload voltages from a similar injectors flow data for voltages below 13v.
from here i tune the ve in at idle and monitor the system voltage.
i create a histogram that plots afr error against system voltage in the same format as the voltage modifier table.
i start recording the idle and then pull the alternator plug which slowly drops the system voltage since the alternator is now not supplying any charge source. i keep doing this until the system voltage gets to 10v which is where i call it quits so i dont kill system components like say the battery, ignition coils, injector coils. leave the voltage offset data from below 10v as the data you swapped in from a similar set.

the idea behind this is if you tell the ecu the injector flows the IFR rate at fully charged then this is where its going to be when you drive assuming all is well. to do this the voltage multiplier is 0 which means there is no flow offset to the IFR table. Most batteries are 6 cell batteries measuring 12.6 volts at full charge which means each cell is 2.1 volts. if a cell drops then it usually shorts an adjacent one out unless you have a spiral cell battery like an optima which keeps them isolated. if an optima shorts a cell then it drops to a max voltage of roughly 10.5 volts, but for most people the standard battery can take out 2 cells which drops the max voltage output to 8.4. this is why you cant start your car when the battery shits itself. most starters need a bare minimum of 10 volts supply (unloaded, no current flowing) to start a battery because they can drop that source 2 volts or more when loaded by the starter. Since the voltage at failure drops below a safe tune-able spot your going to end up fixing the problem before you ever need to run for a substantial period of time requiring that low voltage offset to be correct. now some may say the voltage does vary at startup when the vehicle sits for long periods of time or just over night. to counter that, calibrating to 10 volts allows the system to micro drain over time and still run accurate enough to allow the charge system to pick back up during run time.

I will mention again that this technique is fairly crude and isn't recommended unless your at the very end of all other options, so dont be like i should do this first then work it out. No! i still recommend sending them out for flow testing first, finding a similar data set to test second, and then last chance this way for a possible hail marry.