VE tuning issues, please tell me what im doing wrong

[CptFalcon]

Hello, im in the middle of doing the OLSD tune on my 98 Sonoma. Its an AFR headed 383 sbc 11:1 CR, it has a single plane with a 4150 TB, T56 Magnum etc. Its a 24x SBC running an 0411 with a 2002 F body OS and LS coils. The injectors are Siemens Deka 80's. Im only running a large injector because I plan on adding a Procharger down the road and wanted to buy just one set, I was told you could tune around them. I have my wideband setup right after the header where one of the NBs go.

After going out to do a log I keep finding that no matter what I do my error graph keeps reading pig rich below 55kpa and then goes hard lean right after 55kpa in most spots. Ive tried adding and subtracting fuel to try and smooth it out but the problem never really goes away and I end up with a diagonal line through my graph. I figured the issue must be in the settings somewhere, I used injector data that I was told was right for these, I have run them first at 58 psi then at 43 with no real difference. I was thinking it was an issue with PE being right around 55 kpa. Sorry im not an expert tuner or anything this is only my third car. Any input is appreciated.


98 Sonoma 383.hpt

24-05-13 13-23-14.hpl

[edcmat-l1]

Injector data isn't correct and it's not setup correctly for what I assume is a return style system.

[CptFalcon]

Injector data isn't correct and it's not setup correctly for what I assume is a return style system.

Yes it is return style. I wasn't aware the injector data differed for returnless system. I'm assuming the IFR for a return style will be much closer to 80 lb/hr and 43 psi fuel pressure?

[blindsquirrel]

'Return' meaning it has a vacuum hose from manifold to regulator, and not just that there is a hose for fuel return to the tank, right? It's the presence/absence of the vacuum reference that makes it one or the other, not where it's located or anything.

[CptFalcon]

'Return' meaning it has a vacuum hose from manifold to regulator, and not just that there is a hose for fuel return to the tank, right? It's the presence/absence of the vacuum reference that makes it one or the other, not where it's located or anything.

Yes its an Aeromotive vacuum referenced fpr. I'm reading that the voltage offset needs to be linear with one of these?

[blindsquirrel]

Look at the link in my sig, it doesn't have your injectors but it has both referenced & returnless data right next to each other so the differences in how they are set up are easy to spot.

[CptFalcon]

Look at the link in my sig, it doesn't have your injectors but it has both referenced & returnless data right next to each other so the differences in how they are set up are easy to spot.

Thanks that makes sense. It's basically just gonna be close to 80 lb/hr across the board. These injectors flow 80 at 43 psi. I'm assuming I keep it around 43? I can't see any real reason to run them at 58 psi.

For the offset voltage graph should I just start with one from a factory referenced tune like an O2 express and start there?

Sorry for the dumb questions.

[ns158sl]

No. You need the offset data for those injectors. If you look at blind's spreadsheet, that would be the tables you need, but for the 80 lbers.

[Alvin]

Hello, im in the middle of doing the OLSD tune on my 98 Sonoma. Its an AFR headed 383 sbc 11:1 CR, it has a single plane with a 4150 TB, T56 Magnum etc. Its a 24x SBC running an 0411 with a 2002 F body OS and LS coils. The injectors are Siemens Deka 80's. Im only running a large injector because I plan on adding a Procharger down the road and wanted to buy just one set, I was told you could tune around them. I have my wideband setup right after the header where one of the NBs go.

After going out to do a log I keep finding that no matter what I do my error graph keeps reading pig rich below 55kpa and then goes hard lean right after 55kpa in most spots. Ive tried adding and subtracting fuel to try and smooth it out but the problem never really goes away and I end up with a diagonal line through my graph. I figured the issue must be in the settings somewhere, I used injector data that I was told was right for these, I have run them first at 58 psi then at 43 with no real difference. I was thinking it was an issue with PE being right around 55 kpa. Sorry im not an expert tuner or anything this is only my third car. Any input is appreciated.


98 Sonoma 383.hpt

24-05-13 13-23-14.hpl

Those injectors are fairly old and are "lazy" compared to what is out now days.. You can get them to work just fine .. but having proper injector data is going to be absolutely critical.

But.... First priority when doing large injectors in a GEN 3 there are two settings in the transient section that will cap the injector PW at lower throttle settings especially.

Use the navigator tool to find ECM 2284 and ECM 2282 and zero those out. Some people like to modify this to a smaller value than stock. But I've had no issue zeroing it out. Something must be done to those two settings with large injectors..

[CptFalcon]

Those injectors are fairly old and are "lazy" compared to what is out now days.. You can get them to work just fine .. but having proper injector data is going to be absolutely critical.

But.... First priority when doing large injectors in a GEN 3 there are two settings in the transient section that will cap the injector PW at lower throttle settings especially.

Use the navigator tool to find ECM 2284 and ECM 2282 and zero those out. Some people like to modify this to a smaller value than stock. But I've had no issue zeroing it out. Something must be done to those two settings with large injectors..

Thanks for all the help so far. It appears my offset voltage was correct I just needed to copy the 0 column data to all the other columns. I set the IFR at 80 lbs across the board, left fuel pressure at 43 psi and zerod out 2282 and 2284. After doing this it and taking it out it runs better right off the bat. No more divided histogram and just rich everywhere but completely fixable.

[blindsquirrel]

The 0 kPa column in Gen 3-format data is assuming 58 PSI rail pressure. For 43 PSI, you need to use the 304 kPa Delta column from one of the Gen 4 tables in the spreadsheet. There's no way to work backwards from the Gen 3 format to get data for a rail pressure less than 58 PSI at 0 kPa VAC, there's no table off in that direction.

screenshot.14-05-2024 20.09.48.png

[CptFalcon]

The 0 kPa column in Gen 3-format data is assuming 58 PSI rail pressure. For 43 PSI, you need to use the 304 kPa Delta column from one of the Gen 4 tables in the spreadsheet. There's no way to work backwards from the Gen 3 format to get data for a rail pressure less than 58 PSI at 0 kPa VAC, there's no table off in that direction.

screenshot.14-05-2024 20.09.48.png

Ahh okay i see I will probably bump it up to 58 and try again. It seems a bit less invasive at this point.

[blindsquirrel]

Or, I mean, you could just put the data in that matches that fuel pressure.

screenshot.14-05-2024 20.18.29.png

[CptFalcon]

Or, I mean, you could just put the data in that matches that fuel pressure.

screenshot.14-05-2024 20.18.29.png

Oh wow very good. Is that for 80 lb/hr at 43 PSI? Do you keep the rest of the graph zerod out or copy that over all the columns?

[blindsquirrel]

That's the cells that line up from the Gen 4/304 kPa column, the rest has to be interpolated (across each of the empty cells) to fill out that column, then that column pasted all the way across. Zeroes are only done to make it crystal clear where you have pasted in new numbers as you're working.

You need the Min/Default PW & Short Pulse Adder tables updated with correct data, too. Those are direct copy-paste, no changes needed because of pressure or regulator type.

[blindsquirrel]

screenshot.14-05-2024 20.20.12.png

[SiriusC1024]

This is your tune setup for Deka 80 at 43.5psi if you'd like.

[CptFalcon]

This is your tune setup for Deka 80 at 43.5psi if you'd like.

Awesome thanks so much for for all who gave input. I was able to make it work and the tuning is going smoothly as of now.

[Alvin]

Thanks for all the help so far. It appears my offset voltage was correct I just needed to copy the 0 column data to all the other columns. I set the IFR at 80 lbs across the board, left fuel pressure at 43 psi and zerod out 2282 and 2284. After doing this it and taking it out it runs better right off the bat. No more divided histogram and just rich everywhere but completely fixable.

awesome!