why do my precision 1000cc injectors want to be scaled at 650? where could the problem be or is that just normal in some cars/

 

I replied the following in your other thread (https://www.evolutionm.net/forums/sh...d.php?t=366597)


you need to check out your latencies. they are probably too low for your injector size.

there is a guide on how to rescale your injectors on the ecuflash section. it's very useful. you might even find scalings and latencies for the injectors you have.

did you tune your car for WOT yet? are you having to remove a lot of fuel from the maps at WOT?

 

1000's on gas should be in the 800's and the latencies should be in the .900 range or so. Look at Injector Rehab for the latency list for some starting points. Then follow the trims very close.

 

mis-read title...

 

I just did PTE1000s...

My scaling is 812, and I used the raw numbers from the AEM calculator (not the ones that are scaled back to stock ECU injector scaling!!!)

These are the values I plugged in... ECUflash rounded some of them out. Car has outstanding idle and fuel trims:

edit: lol, it seems our values are the same... just slightly different scaling. When I tried 835 scaling, the car was adding lots of fuel.

 

I also have Precision 1000cc that I am trying to scale. They are proving to be very annoying as the normal conventions are not working properly. I am following this guide:

1. Choose a global setting (ECUFlash injector scaling number)
2. Log trims at idle and cruise
3. If trims are roughly the same, but positive, then you need to increase your global fueling, or in terms of ECUFlash, you need to lower your injector scaling number.
4. If both trims are roughly the same, but negative, then you need to descrease your global fueling, or in terms of ECUFlash, you need to raise your injector scaling number.
5. If idle trim is more positive than cruise trim, then you need to increase the dead time, or in terms of ECUFlash, you need to increase the latency value.
6. If the idle trim is less positive than the cruise trim, you need to decrease the deadtime, or in terms of ECUFlash, you need to decrease the latency value.

I have scaled a set of 680's no problem but I can not get these 1000's dialed in. I will list what I tried: latencies, scaling, and trims:

3.312
2.184
1.632
1.200
.864
.600
.552

Scaling: 860

Low Trim: -2.84
Mid Trim: -11.27

3.312
2.184
1.632
1.152
.84
.600
.552

Scaling: 860

Low Trim: .10
Mid Trim: -12.05

3.312
2.184
1.632
1.152
.912
.600
.552

Scaling: 886

Low Trim: 6
Mid Trim: -4


3.312
2.184
1.632
1.152
.912
.600
.552

Scaling: 914

Low Trim: -7
Mid Trim: -3

3.312
2.184
1.632
1.152
.912
.600
.552

Scaling: 943

Low Trim: -.29
Mid Trim: -6.9

I have also tried the values listed in the AEM table and they are way off. I have reset the trims by disconnecting the battery every time I upload a new ROM. I then let it idle for a few minutes and then drive about 20 min on the highway and then let it idle again. I am logging the trims the entire time with EvoScan. Can anyone offer assistance as adjusting the latencies and scaling don't seem to be producing the correct results. Thanks

 

Oops!!!

 

What were your trims?

 

http://injector-rehab.com/kbse/lag.htm

 

Something everyone needs to remember is the AEM is a peak and hold injector driver and the Ecu is a saturated injector driver system. The values in the AEM wizard are for the AEM not the stock ECU. I was chasing my tail trying to dial in my FIC 850's until Mr Fred told me about this and then gave me some sample values to start from. Also once you make a change to your latencies you need to recheck your scaling, and once you think you have everything correct go back and check everything again! LOL

Josh

 

thats some good info jmelocik

 

I just checked them on lunch with Fostytou...

LTFT Low was 4.61%, LTFT Mid -3.43

 

Could you elaborate a little bit more on this? The only reason I ask is because my car runs quite good(see above post) with the AEM latencies and the 812 scaling

 

Awesome thanks man!

 

As best as I understand it, sure. The AEM is a peak and hold driver system which means the AEM EMS will give the signal at a different time based on that being calibrated into the system. (probably milliseconds difference). I am definately not saying that you can't get good idle quality or have a good, strong running car with these values. I do know from my personal experience that I had a constant problem with P0300 both at idle and cruise on the highway. Once I found that my latencies where off by a good bit, and made the necessary adjustments, I only throw the P0300 once in a while in around the town driving. I am still dialing mine in a little closer now so hopefully I will be rid of P0300 all together!! I have been in contact with some of the ECU gurus on here in an attempt to understand most of what I have learned! LOL I hope this has helped and not just confused you like it did me the first time I read it.

Josh