If you're getting corrections that large (and have lowered TEMIN), then KRKTE and TVUB aren't setup properly.

The issue though is that at low load/idle the injector on time stays dead constant and it seems like something else is preventing it from going lower. 

At low load I can literally see in the logs the same injector on time being used for 3.5g/s MAF and 4.5 g/s MAF (just giving it a touch of throttle above idle)

Bring up the load a little and very little correction, full throttle and very little correction so KRKTE looks good.

I'm guessing when you said you read the entire section on injector on time calculation, you meant the S4wiki.
If you look around on this forum there is a thread or 2 where somebody has already dialed in some 1000cc injectors, EV14 I think. Maybe they had the same problem and solved it. use TVUB, KRKTE, FKKVS, and TEMIN as search words in the search box of the main forum page or use Google and put in the search:   site:nefariousmotorsports.com <----then after here, put in whatever search words or phrases.

You are probably wasting your time with TEMIN though. Unless the engine requires for injector on time less than TEMIN, lowering the value of TEMIN will do nothing. Stock TEMIN for my HSbox is .7493 --->IF<--- I defined it properly in the definition file. I have never seen injector on time that low ever on my 1.8t. I'm running 550cc injectors though but I don't think you need to mess with TEMIN unless you are going 2000cc+.
Which 7.5box are you working with? What is the address for TEMIN in your definition file? I would like to confirm the address in mine if possible.

the fuel system for ME7.5(mine anyway AWP motor) is sequential, so fuel pressure is referenced by boost! The ECU sends PWM signals to the fuel pump to raise the fuel pressure at a ratio of roughly 1 to 1 in psi. Before this happens the fuel reg references vacuum. So this may explain why you don't see changes in the injector on time like you explained and are expecting.

He's set TEMIN to .3ms, I'd think that would be sufficiently low (for idle at the very least).

I think he's using wacky TVUB values or hasn't adjusted for a change in fuel pressure.

It is 4bar (58psi) returnless on an Audi.  I have read 11.40 Calculation of injection time.

I've run several different sizes of injectors and never had issues adjusting TVUB/KRKTE before.

I've tried everything from stock TVUB (very low) to the dead times from the data sheet (quite large) @12v for example that is from .611 to well over 1.0  It idles the same... always 1.8x ms.

According to the documentation, I think in theory you're just supposed to use the dead times from the data sheet at the correct pressure and then FRLFSDP is supposed to take care of the rest in terms of the ambient reference pressure.  In these files though it does seem that using the measured dead times would give way too high an injection time and when stock values are compared to stock manifold referenced TVUB values in other files they seem generally lower.

It does seem that it is not actually in closed loop, it just mindlessly runs rich etc and the additive trim does not move off of zero.  I'm pretty confident that something is being calculated that is below a threshold and then wham toss it out and plug in a default value.  How else do you get the exact same injector on time for anything between 3.5-4.5g/s?

As far as finding TEMIN/VA in all the files I've seen they are just before the TVUB axis values, one or two 16bit values just before 05 71 8E AA C7 E3



 

Yes I believe rk_w is the same, same day, same ambient temp, idle to full temp, just a higher idle set point.

Once you go high enough with the pedal to generate a pulsewidth at or above 2ms happiness.

So you're saying that TEMIN should be set so that in conjunction with TVUB the smallest pulse width that could be generated is above the low slope "knee" in the linear deviation correct?

For example in the 6th plot down or so, "Linearity Deviation @ 4 Bar" -the minimum should never be below 1.5ms or so and anywhere between there and 2ms should expect hefty adjustments with FKKVS?

http://www.injectordynamics.com/ID1000.html#Dynamic Flow Characteristics - 4 Bar (58.0 psi)

If rk_w is the same, then most likely ti will be the same.


Yes, TEMIN is the minimum final pulsewidth.


Yup.

Do they provide any hard data (not just graphs) other than static flow and battery compensation?