ECMlink InjBatteryAdj vs global deadtime or deadtime offset field

[We're on Boost]

InjBatteryAdj - Does this table do absolutely nothing if you have a non-zero number for "Global deadtime" on the Fuel tab?

The wiki for InjBatteryAdj seems to say that, but on the help page in the application it sounds like you can use both together.

The InjBatteryAdj wiki has a note that says "NOTE: That list is total deadtime. To use with ECMLink, set the deadtime offset field on the Fuel tab to zero." http://www.ecmtuning.com/wiki/injbatadj

So the InjBatteryAdj list is non-functional if you have a number in the "Global deadtime" field?

 

[jed344]

It does the same thing as dead time accept applies different amounts based off voltage vs dead time that is applied at any voltage. What ever your dead time value is then is added or subtracted from the injbat adjust table. When you buy injectors and they have a sheet you can plug those values into inj bat adjust and get very close right off the bat. When injectors are used without a sheet i often used dead time to find correct settings then zero dead time and add those values to inj bat adjust.

 

[We're on Boost]

What ever your dead time value is then is added or subtracted from the injbat adjust table.

So you are saying they both work, together. They add to each other basically.
Well that is what makes sense and that is what I always thought they should do.

If so, then you don't need to set the global deadtime to 0.
And the list is not total deadtime, unless you set the global to 0. Then the list would be total.

So that note is weird.

Anyway I was worried that my InjBatteryAdj was doing nothing just because I have a number in the field for Global Deadtime.

 

[1990TSIAWDTALON]

And sometimes you need a negative number in the dead time field. My tuner had mine at -75. I didn't know until then. He had me plug in all of my #'s from FIC then fine tuned with the DT. IDK if we had finished, as my car started its transmission problem and then when that was finally replaced, the car was having fueling issues so I quit until I could get it all lined out. I was about ready to go over it with him again if he didn't mind but now have a trans issue again.
Just thought I'd add the fact you can use a negative number also.

 

[ist dwa]

Stay away from the INJbattery adjust table, it's not necessary. I never use the FIC settings nor ever use that table it is pointless. The car only runs at ~13 volts, so the voltage is steady, (think logically; does changing inj voltage at 7 volts change anything? Set your deadtime once and forget it.

NOW, if you are Jeff Buch and Boostin setting records and you're fine tuning PER CYLINDER trying to get exact air fuels because you're making 2000million HP in a 4G....then yes. Your 500-800hp doesn't care. KISS!

 

[jed344]

Stay away from the INJbattery adjust table, it's not necessary. I never use the FIC settings nor ever use that table it is pointless. The car only runs at ~13 volts, so the voltage is steady, (think logically; does changing inj voltage at 7 volts change anything? Set your deadtime once and forget it.

NOW, if you are Jeff Buch and Boostin setting records and you're fine tuning PER CYLINDER trying to get exact air fuels because you're making 2000million HP in a 4G....then yes. Your 500-800hp doesn't care. KISS!

When I have a sheet to look at I normally use that data for inj bat adjust then fine tune it with dead time. Either way ends up with same result.

 

[ist dwa]

When I have a sheet to look at I normally use that data for inj bat adjust then fine tune it with dead time. Either way ends up with same result.

Exactly my point, you put them in, they aren't right and end up adjusting the dead time any ways. That's two variables for the same result versus ONE. KISS!!

 

[AWD-Tony]

If you have it, why not use it? It’s the most accurate starting point given by the manufacturer. Sure you have other issues if you’re not at 13-14v, but if you have to drive home at 10v, it’ll get you home.

 

[Tyeler18]

Definitely run into plenty of times where the voltage offset has paid off. Weak/low battery, my engine doesn't start at 13v, it cranks at 12 and bumps to the 14v. Alternator dying mid pull/trip home.

 

[danl]

There are many scenarios where battery voltage drops well below normal and the alternator can not keep up. This typically happens at idle. The ECMLink page the OP linked to described the scenario where battery voltage drops when using the power windows. Another scenario is when turning on the headlights or blower fan motor. Yet another example is when the cooling fan kicks on or the rear defroster turns on. Finally the most important area where this becomes important is when cranking the starter. As I mentioned in another post relatively recently, my latency numbers were off by 1000ms when cranking, causing starting problems.

 

[We're on Boost]

And sometimes you need a negative number in the dead time field. My tuner had mine at -75. I didn't know until then. He had me plug in all of my #'s from FIC then fine tuned with the DT. IDK if we had finished, as my car started its transmission problem ...
Just thought I'd add the fact you can use a negative number also.

I noticed that neg number in your global deadtime field in a log you posted just a few weeks ago!
Then I looked at an FIC flow match sheet that I have lying around from 2009, and noticed that at 14 volts and above, the closing actually takes more time than the opening. . Negative deadtime.
Anyway I get it that you aren't saying that's the reason for your negative deadtime. You are saying that he set up deadtime a certain way first, and then did his last tweak of it with just the global and it ended up going a little negative.

I also get it what everybody is saying, that you can use both together, or use just the list with global set to 0, or even you could use just the global if you don't care about cold starts and stuff like that, probably.

And it's cold starts that got me looking at this in the first place. Because I saw that table and I thought, man I sure would like to add about 2ms (2,000 microseconds) to my InjOn time when the batt voltage is between 10.0 and 11.0 volts. Because my batt voltage is always about 10.5 or so during cold start cranking, and I need more fuel there I think. My cold starts have always been very slow ever since I started using DSMlink. I mean I grew up with chokes on carbs on a variety of 2-stroke and 4-stroke motors, and I know a few things about cold starts!

But that InjBatteryAdj table isn't configured very well for how I would want to do it. It would need probably 2 more rows. A row for 10 volts and a row for 11 volts added to the rows that are there.
That way I could bump up the InjOn time at 10 volts, hold it high until 11 volts, then drop it back down to "normal" at 12 volts and the rest of the way up.

Well since that isn't going to happen I should probably just try to do it with CrankingFuelAdj instead, and that is maybe more intended for what I'm try to do anyway. But my original idea was to try doing it with some combination of CrankingFuelAdj and InjBatteryAdj. Because the battery voltage comes up above 11 volts almost immediately when the engine starts to fire. That's kind of an ideal cutoff point for my added 2ms.

Are you guys finding that CrankingFuelAdj works the way it's supposed to? For that matter, how's it supposed to work? I mean, the number you change in it is labeled Adj(%). Adjust percent - percent of what? For example if you set a knob to 300% you are apparently tripling something. What is it that you are tripling? In the changelog for it which is 3.26.90 (02/28/2013) it says "adjustments to the temperature-based cranking fuel table in the ECU". That doesnt' really explain it to me because I don't know what that table looks like before it's "adjusted" so I don't know how much to expect from tripling it. Know what I mean?

​

 

[1990TSIAWDTALON]

Well, I can say that no matter the temperature, and I have no FIAV, my car fires right up and I can go inside or sit in it while she warms up when it's tuned with the battery offsets. I won't change a thing because it is so reliable.
Thank you little Blue Car!!!

 

[AWD-Tony]

There are many scenarios where battery voltage drops well below normal and the alternator can not keep up. This typically happens at idle. The ECMLink page the OP linked to described the scenario where battery voltage drops when using the power windows. Another scenario is when turning on the headlights or blower fan motor. Yet another example is when the cooling fan kicks on or the rear defroster turns on. Finally the most important area where this becomes important is when cranking the starter. As I mentioned in another post relatively recently, my latency numbers were off by 1000ms when cranking, causing starting problems.

Very good point

 

[We're on Boost]

Well, I can say that no matter the temperature, and I have no FIAV, my car fires right up and I can go inside or sit in it while she warms up when it's tuned with the battery offsets. I won't change a thing because it is so reliable.
Thank you little Blue Car!!!

Marty, the latest log I have for your blue car is dated 2021.10.04 and it was when you were looking at the lean condition so there was still that problem with it.
It might help me to look at a recent log of yours with that problem fixed.
In that log from 10.04 I see it was kind of a "warm" cold start (76 deg) and you cranked it 4 times.
So it's better than that now right?
I see your cranking voltage is about 10.5 like mine.
Anyway if you have a few dull moments sometime haha, maybe you could log a cold start and ship me the log by private message or something. I can think of a few things I'd like to look at in it, for what we've been talking about. No hurry! I'm replacing my main cooling fan right now and that's going to go slow because I'll probably end up making my own brackets for it, and the fan doesn't even get here until Friday.

 

[1990TSIAWDTALON]

I could do it right now but let me pull one in the morning when the shop is cold. I don't mind one bit. I'd be thrilled if it helped anyone just hop in and start the car, no pedaling it, and it just runs. And I have these huge injectors and shit. If you tune to stoich at idle after your global is set, it usually works out the way mine does. All of mine do or did.
I'm off work tomorrow so send me a reminder PLEASE .
PM sent.

 

[ist dwa]

Another scenario is when turning on the headlights or blower fan motor. Yet another example is when the cooling fan kicks on or the rear defroster turns on.

This is the real purpose of that table, not for stupid FIC figures. You are supposed to log adjbattery and when large electrical loads are applied you can adjust the inj bat to help compensate, we all know at idle with lights, wipers, rear defrost etc the RPMS drop, and props if you take the time to tune that. After using LINK for 12 years I haven't needed it for those situations honestly. I run big cams and the idle needs to be up regardless so if my 1100rpm idle settles to 900 with all the electronics full tilt who cares. I guess if you want to have your car idle at 750 this would be a thing but then your car is gonna stall every time you let of the gas so again the idle has to be up.

If you are having starting issues this table should be ignored and use the cranking adjust table which I have since the firmware update went out a long time ago, and keep in mind this was because of ethanol, on pump gas, please no cranking adjustments are needed.

I've fixed so many tunes where the first thing I do is reset this table back to stock because it's always wrong.

 

[jed344]

I still prefer to use INJ bat adjust, to each there own. You can take what ever you have in dead time and then apply that to INJ bat adjust to end up with same result, as said above starting you need cranking fuel adjust and if above idle rpm then you are looking at SD or maf comp. All this assumes you already have injectors global set correctly. When everything is done correctly they run great. My 10:1 motor fires right up and idles normally at any temp with no fiav. Only times I run into issues is when there is no ISC. Stock DSM charging system is not very good. When using a galant 90 amp alternator and wiring upgrade it does much better. I idle at 14.1-14.3 and at full tilt 8,500rpm+ lowest I have seen is 13.8.

 

[Kryndon]

This thread is so good and relevant to the issues I'm having currently... Long cold cranks, AFRs keep not matching up and Fuel Trims not wanting to settle.

One thing I noticed is, if I leave my InjBatt table stock and only up the Global Deadtime till I get a steady idle and cruise, the number I've set there would very closely match the number I would need to add on top in the Inj Batt Adjust table to reach the FIC sheet data. So like the others are saying, it mimics itself. However, it's best to input your specific voltage offsets and then add smaller amounts into global, especially if your charging system isn't upgraded.

I am once more gonna fully reset my tune and try dialing it all in again. Hopefully we can keep this thread going because this still remains an important part of tuning with DSMlink and dialing in injectors!