Here are the scalings and latenceys i have used for RC750's using Tesco 99 all trims within 1%

Scaling size 696

3.312
2.184
1.416
1.032
0.792
0.480
0.360

 

Hi guys,

I just decided to check my trims and found out that I am a bit off on the Mid Trim.

I have PTE 780 with global scaling of: 696

Here are my latencies:

3.504
2.184
1.224
0.960
0.744
0.552
0.432

Here are the trims (From left to right: Low, Mid, High and O2 or 0C, 0D, 0E and 0F) after a 10-15 min cruise:

I read the instructions provided in the first pages but I am confused if I need to increase the global scaling or just the 11V and 14V latencies. Any guidance?

Thanks in advanced!

 

Try leaning out the global, IE: going up the next size in injector global. It will affect your mid more than the low, but you will have to then make a small adjustment to your low after you see how things pan out.

 

Hi dan,

I followed your advice and ended up increasing the global scaling to 713 with the following latencies:

3.504
2.184
1.224
0.96
0.792
0.552
0.432

I also tweaked the MAF scaling in order to reach solids Trims at idle.

Note: PTE 780

Thanks a lot for the advice!

 

Here is mine,, lil different than some of the others....

pte 780's

665 injector size scaling

injector battery voltage latency compensation
3.816
2.184
1.416
0.96
0.696
0.48
0.36

 

To get solid trims at idle you should add/subtract to your latencies.

 

I'm having issues scaling a set of FIC 850s. I've tried all sorts of scaling figures under the son, from a low as 513 to as high as 770. I've used several injector latency figures listed. I gathered that increasing latency figures adds fuel and subtract removes fuel. To that end I don't understand why most people are increasing the latency numbers with bigger injectors as it would appear the latency would need to be reduced. As far as the scaling number is concerned, I assume the same principle applies. Each attempt has result in the same thing, the car barely runs. In fact its so bad that the spark plugs fowl very, very frequently to the point where I need to removed them and clean the tips off with a torch.

The issue is that with each attempt to remedy the problem nothing seems to change as far as the a/f ratio is concerned. Logging the LC-1 shows values at 10.3xx to 10.8xx to idle with the fuel trims not even registering. I had the O2 feedback show a few -24s on occasion but that is it. Obviously the car is running WAY rich but, the ECU doesn't seem to be responding to any attempt I make at scaling these damn injectors.

I haven't ruled out a faulty ECU but, was curious to know if anyone has any suggestions on either to continue to attempt to scale the injectors or to ensure the ECU is in fact operating correctly.

Any help would be appreciated as I've been stuck on this issue for sometime now. I have replaced the front narrowband signal with a LC-1 as the, one of many reasons, the front O2 sensor was bad.

 

You should have started with this. I would guess you did something wrong when you wired up your LC-1 NB output to ECU or something is wrong with NB settings you put in your LC-1.

You can give this a try in the meanwhile — disable your closed loop (put high temp in Temp Req'd for Closed Loop table) and try to tune those to ~14.7 at idle with latency and scaling. Just use someone's settings from this thread for similar injectors as a start.
If you have aftermarket intake you may want to look into adjusting MAF scaling table as well to get'er idle right.

 

The problem is that the scaling and latency values you've tried are still way out of range. If idle is running really rich, then its likely the latency as it has the greatest effect on IPW at idle.

I've directly observed the latency of many large injectors using a benchtop setup with an oscilloscope. Bigger injectors definitely have higher latency values (slower to open).

 

From reading through the LC-1 manual it appears as though the analog output #1 is preprogrammed to simulate a narrowband O2 sensor so I shouldn't have to adjust anything in the LM Programmer, correct?

I had considered disabling closed loop and actually tried it but, I may have set the temperature to high. I set it at 999 just to get it off the chart and out of the way. The car didn't react any differently. I had used several of the FIC 850 settings in this thread but, all to no avail.

I knew the latency and scaling are way off but, I'm not 100% sure which way to go. I remember reading earlier in this post with regards to latencies that when adding voltage you are adding fuel and when you reduce the voltage you are reducing the fuel. With regards to scaling, does it work the same (as in the smaller scaling number the less fuel and vice versa)?

The problem I'm having is that I've used all the settings posted on here for FIC 850s and have gotten nothing even relatively in the ball park, which is worrisome since it seems like many have used those numbers to great success. I guess it comes down to me just not quite fully understanding what changing the latency and scaling numbers actually do in terms of fuel delivery. Any input would be appreciated.

 

Smaller scaling is more fuel. Bigger latency is more fuel.

 

not sure if i posted these or not... but these worked for me

Scaled at 770

3.48
1.92
1.368
1.008
0.768
0.6
0.456

 

Thats the piece I was missing. I thought it was the opposite when it came to scaling as in smaller equals less fuel. Thanks for that.

I actually did try your settings but, they still were way too rich. My trims weren't event registering

 

Adam my man how the heck are ya. Yea latency is essentially dead time. So less dead time more fuel more dead tim less fuel. I did notice messing with my 880's messing with the latencies effected Idle more than anything.

Here's the 1,000,000 dollar ? though did you put an aftermarket intake on the car sametime as the injectors

 

Luke, long time huh?

Larger latencies increase fuel and smaller latencies decrease fuel (?). Now when you talk in dead time terms it sounds like when you increase the dead time it is actually reducing the latency in ECUFlash terms and vice versa, right?

There is a long story behind this car I'm working on. I completely rebuilt the entire motor with aftermarket parts and a 35R turbo with a short suction pipe, OEM MAF and filter. I know where your going with this though i think - MAF scaling. The problem is the trims aren't even registering because of the injectors. If I try to rescale now the scaling I would need would be off the charts.

The other thing though is I'm not 100% convinced that the ECU is working properly.