Alright! It's to my understanding, by the recent post, that if my fuel trim low (-4) and fuel trim mid (-4) are both negitive, I must up my injector scaling. My scaling is currently at 770. I'm running PTE 880. Am I right or do I have to change latencies as well?

 

no... nick, -4 is well within tolerance... id leave your scaling alone unless your pursuit for perfection leaves you in need of adjustments... in which case add 4% to your trims

 

Anyone have the latency numbers for RC 750 injectors?

 

ive got FIC 750's... dont know how close they'd be

 

i realy need help with my FIC 750's....

 

scaled at 650

3.312
2.04
1.296
0.696
0.624
0.408
0.192

 

Thanks!!!

 

try it out... if it isnt IT, its close. I logged it the other day on the dyno during a tune. The idle afr's were dead solid 14.7 to 15.1 and cruise in 4th gear were the same.

 

That's what fuel trims are for.

The fuel trim values are what is important, but of course I am sure you know this.

 

Has any one ever scaled FIC 950's. I know they are in the AEM manual but I just want to see how that compares to real world. I have to drive 100 miles to my tuner after I install my injectors. I don't want any problems

 

im pretty sure

fuel trims

low 100
mid 92
high 100

 

Well, I have read every damn post I could find and went out logging things the past two days. Made some adjustments and this is where I'm at:

PTE 880's scaled to 770

STFT(mid)=.7%
IPW(mid)=2.3ms CRUISE
LTFT(mid)=.7%

STFT(low)=.5%
IPW(low)=1.5ms IDLE
LTFT(low)=12.6%

4.6875 = 3.696
7.03125 = 2.568
9.375 = 1.704
11.7188 = 1.224 LATENCY VALUES
14.0625 = .960
16.4062 = .552
18.6768 = .432


Anyone have any thoughts/suggestions in order for me to pull my LTFT(low) in line without f-ing up my cruise, etc.?

 

Yes, you would add latency, which would bring both your LTFT Lo and Mid down, but it would bring your LTFT Lo down faster than the mid. Once they are close to being equal, then you would bring them both back to 0 with injector scaling. I think I posted the steps a few times around here and even on page 5 of this thread.

However, this is somewhat important (even though I just went through a 5 page thread arguing with Buschur and his fanboys about it in the engine/turbo/drivetrain section):

Make sure that you aren't running a breather filer on your valve cover where your breather hose should be connected to your turbo intake pipe. If you don't have the breather hose connected and are using a filter, you are letting unmetered air after the MAF into the IM from the PCV valve during high vacuum conditions, like idle and some cruising. This can cause positive idle trims like you are seeing.

If you don't want to follow these steps or you are running a breather filter, etc, you can still fix it with the MAF scaling. I cosider this more of a bandaid fix, since maf scaling should only be done if the maf readings are truly off. But, to fix just your idle trims, you would alter the cell of the maf table at the HZ that you are idling at. Please refer to the maf scaling thread for detailed instructions.


Eric

 

scaled at 770

3.648
2.016
1.392
0.984
0.744
0.576
0.456

 

No Breather filter, although I do have a Perrin catch can. Now, when increasing the latency values, I am to adjust the values UNDER 14v, correct? The only issue I foresee with doing this is that at idle, my voltages rarely drop below 14. Thoughts?