I just installed precision 780cc injectors. If i raise the injector scaling in ECUflash over stock(513) my WBO2 reads off the chart LEAN...

This is my first time working with bigger injectors, so is this more complicated than i thought? By changing the injector scaling is that number changing the whole way my fuel/timing map runs? Like having a big mathematical equation to work out and then u change the first number and everything is all whacked out

Help Appreciated as i need my ca running tonite

Thanx
J

 

What are your fuel trims telling you?

U need to increase the scaling and probably reduce the latencies.

However follow the proceedure on page 5 (by Eric) of the Injector scaling thread (by Bez)

 

i will read that thread now... i jus let the car idle and it was leaner than 18(as lean as my wideband goes)

 

^^also, i only let the car run for maximum of 10 seconds so i didnt log it, but i will mess with it tomorrow. i jus read that thread, very helpful

 

ok, i adjusted the voltage latencies, and scaled injectors to 609...

My STFT averages 125% at idle, if I raise the scaling the STFT raises also... Don't I need to get that number as close as possible to 100?? how do i accomplish this?

Also idle and cruise are ABOUT the same

 

Start with more latency at 14v, what value are you currently using?

 

my current value at 14v is .600........ I will raise and test right now

 

One thing that helped me was working the 11 an 14 cells. go opposite a large number to create a reference point to zero in in the target trim setting in between that. Also sometimes you might have to go maybe 40% under your rated flow number. Well thats how it worked out for me at least.

try these on your 14- 18 cells
0.912
0.696
0.48
Im scaled at 680 for 740s just to give you a ballpark

 

These values have previously reported as yeilding good results with PTE780s:
scaling:680
4.7v=3.504
7.0v=1.872
9.4v=1.224
11.7v=0.960
14.0v=0.774
16.4v=0.552
18.6v=0.432

cheers & luck

 

I will try this later as i got my car runnin pretty darn good right now...this is what i have:
9.4v=1.368
11.7v=.888
14v=.624
16.4v=.408
18.7v=.288
scaling=609

Thanks for all the input it helped tremendously!

However! i have a new problem now! I put in 1000cc injectors on my buddies car today and it took me a long while to get the car to idle, now it idles, but thats it! I try to drive and it goes pigrich and doesnt move, also when i raise the rpms in neutral the AFR's go crazy.
here is the table:
4.7V=3.312
7v= 1.680
9.4v= 1.344
11.7v= 1.104
14v=0.792
16.4v= 0.360
18.7v= 0.240
scaling=812

 

raise your scaling more, many have 1000s scaled from 860-914. Start with 860 and see where your fuel trims go.

 

Each time to make a change to the latencies or scaling try disconnecting your battery. Then turn the key to erase any stored memory. Then start the car (might have to throttle it a bit at first) and start logging. You will see the STFT drop to -25 then the mid and low LTFT will start to change. They should stabilize. Once they do then you will have your adjustment stored in the rom. This is the procedure I used and my trims are near perfect 0. I too have 780s...my settings are....

Scaling....696
Latencies....
3.312
2.04
1.296
0.912
0.792
0.6
0.336

 

cool, thanks for the info... i'll try to get my buddies car running today and ill let u all know how it goes... i will also tweak mine again and try the 2 recommended tables posted

 

What are you using to log? If that is an older version of evoscan you should update the xml data to have the correct formula for your trims.....makes it much easier.

(the newer versions of evoscan are updated)

Also when I did my injectors the first time (850's) I threw in some guesstimates for latencies and scaling. Then took the car out and just rolled into wot long enough to see the afr and then kept adjusting my scaling until my afr with the new injectors were close to the afr from the old injectors without changing the fuel map (other than some minor tweaks once dialed in)

Then I dialed in latencies by using trims until I had them +/- 5%......worked well for me and made it a heck of a lot easier and didnt take long at all. I learned that from my friend who has a dsm - he has used this way of dialing injectors many times with success......

 

(the newer versions of evoscan are updated)
what he said


Never thought of doing that, that should make quick work of the upgrade. Do you make more than one roll-wot??