Added 42# injector need tuning help

[svede1212]

put in some ford green tops and i used the numbers from the spread sheet and it ran really lean. i multiplied by .9
(43.65182 43.89984 44.20987 44.45789 44.70591 44.95393 45.26396 45.51198 45.76000 46.00803 46.31805 46.56608 46.81410 47.06212 47.31014 47.55816 47.80618)
and it idles great (50 kpa) and runs on the freeway at 50-55kpa with dead on afr. on WOT the afr dropped to 10 (or maybe lower, that's the basement of my wideband set up). on low kpa it's very lean (about 17.5 afr). should i skew the slope and bring the bottom end up and the top end down? or should i bump up the adder for the low end and adjust the top? or fix it with the VE table? or all of the above?

[Russ K]

I see that you have the 1 bar SD OS, is your Maf unplugged? Your Maf fail freq is still at the stock 13500 hz. Are you sure your in SD mode? Your IFR table looks about right for the 42# injectors.

You have way too much spark timing (high octane table).

Russ Kemp

[WS6FirebirdTA00]

put in the correct IFR for those injectors and tune your other tables.

[svede1212]

MAF is on the bench . i lowered my spark a bit altho i was trapping about 114 the way it was with no knock. these injectors are driving me nuts! my VE/AFR was dead on with my 28#s. i scaled the crap out of the the 42# SVOs, my 80 kpa is now up to 69 and my 0 kpa is 33.5 and altho i get a good afr, at ~50-55 kpa at WOT i get an afr of 10 (or less) and lower then 50 kpa it's too lean. it's like they have an on, off and middle and nothing else. do i have to adjust the pulse width or something else? i'm going crazy with this. look at 5 minutes into the log. when i floor it the afr drops thru the floor . i think i need sleep

[svede1212]

put in the correct AFR for those injectors and tune your other tables.

i guess i'm going to have to try that. thanks

[WS6FirebirdTA00]

You will need to tweak with the injector offset table as well.

Those injectors support a decent amount of power. You can do some reading here to help:

http://www.hptuners.com/forum/showthread.php?t=9148

[Russ K]

I think you have a wideband issue. At cruise your wideband is reading a steady 17.49. An engine will surge at that lean of an AFR.

Russ Kemp

[svede1212]

well i'm at least making headway. my lean was helped a lot by multiplying my short pulse adder by 1.5. now on cruise it's closer to commanded.i think it was pulsing so quick it wasn't letting much gas thru. i'll check that wideband but it was working great an hour before i put the injectors in...

[svede1212]

well, i don't know what happened but i plugged in the original numbers (i think they were like from 48.xxx to 53.xxx) and the fueling thing is starting to look like it's sorting out. i'll have to get a few logs the get it dialed in but at least it's on its way now. the only issue i have is on decel/low MAP it runs rich as the injector gets to 1.8 and still gives too much fuel. at least i know that my wideband is still good and i'm just down to the nit picking. i'll try adjusting the short pulse adder or turning on my DFCO after i get done with the VE table and see if that helps but i really don't like the popping noises so i may just sacrifice a little gas for peace of mind. thanks to Russ and WS6 for trying to help me out.