Lurius

iTrader: (7)

How do I go about fixing this? I am trying to fix loads of other problems I apparently have with tune since the last tuner worked on it.. Its just bugging me that I cant seem to get it running like ti should at track.. Best I had last visit was like 8.4's in 1/8th.. thats with the 411's in rear and fresh tranny.. before that I had once gotten an 8.2.. but I know its got more in it, if I could only get this tune corrected.

trever1t

iTrader: (14)

you need to find the correct scale for your IFR table and take it from there, which will include re-adjusting your VE among other things. Take it from the bottom, slowly.

Lurius

iTrader: (7)

Ok, doing a little research I found that GM never released the IFR tables for these injectors since they were never put into road use vehicles, and only intended for marine/offroad use..

I also found this:
8.1 Marine Injectors
Part Number 17113739 (OE Part # 25176061)
Direct fit for short G.M. LS1 SUV injectors
Static flow @ 37.95lb/hr @ 43.5PSI / 300KPa (4.31 g/s = 398cc/min)
Static flow @ 43.82lb/hr @ 58PSI / 400KPa (4.97 g/s = 460cc/min) *
Dynamic flow (2.0ms/10.0 ms(pulse width / rep rate)) 6.0 lb/hr @ 43.5PSI (0.748 g/s @ 300KPa)
Coil Resistance: High Impedance / High-Z (No ECM driver modifications required)

That was taken from silveradoss.com

Seems a guy there used 43.82lb/hr across the table for his IFR table.. Giving this a try.. and going to try and learn how to do VE tables now.

When, if ever, should changes be made to the Injector offset vs battery voltage vs. KPA VAC tables?

motion427

iTrader: (1)

I have an excel file that can set the injector flow value.
I have an 04 LQ9. I installed those 42lbs marine injectors.I rescaled them with this file.My VE table was only off by 5-8%.

I set mine
43.5
58
37.95

motion427

iTrader: (1)

Here you go,Some Southern Tuner gave this to me.

Lurius

iTrader: (7)

Thanks, but these are the 8.1 marine injectors, not the 8.1L truck injectors.. i think they are different as these are the 43lb/hr injectors, that file looked like they were smaller, can someone confirm this for me?

Thanks!

motion427

iTrader: (1)

The 8.1L truck injectors.I think they are 31 lbs.You could check a 8.1L truck file.

trever1t

iTrader: (14)

You have a returnless fuel system, right? You want the IFR scaled low to high as kPa increases left to right across the table. Having the table with the number same all across is for return style fuel systems.

I highly suggest you stop and read a lot more before continuing.

motion427

iTrader: (1)

How come I don't see the LTFT,STFT,and the 02's on that log file ?
What trever1T wrote,if it's a returnless, the IFR is scaled backward on that file.

03sierraslt

iTrader: (22)

See this link
https://www.performancetrucks.net/fo...d.php?t=429600

Same issues in another thread. You are going to have to change the IFR table, I posted the settings that I used with the same injectors. You should not have to change any other injector settings. You are going to have to tune your VE and MAF to get you AFR where it should be after resetting the injector settings to what they should be. Set them and leave them. Tune the VE first with the MAF disabled and then enable the MAF and any error you have in fueling will be in the MAF scaling. HPT forums have all this info, do a search there and be prepared to start reading. I never had to change any other injector settings until I went to 72lb injectors.


Disclaimer, the injector settings that I posted are for a Returnless fuel system.