New to tuning. Need help tuning KA-T so I can get to dyno.

[Sofa King]

So, as the title suggests, i'm new to nistune and tuning in general. I need to get my car to the dyno to have it professionally tuned, but it's roughly a 2 hour trip.

So, first, here's my setup.

-1992 240sx FB.
-Stock Bottom/Top end KA. Rebuilt ~4000 miles ago.
-Injector Dynamics 725cc top feed injectors
-Xcessive intake manifold (maintained and relocated IACV. PCV is venting to catch can/atmosphere. Valve cover is venting to catch can/atmosphere)
-Z32 MAFS
-GT3076R-WG (.86 ar variant)
-Greddy TYpe-RS BOV
-NGK IX Iridiums (1 step colder)
-Innovate Wideband
-Walbro 255
-Greddy Profec B Spec II EBC
-Much larger alum Radiator w/dual electric fan shroud.
-Adjustable FPR


Anyway. Over this most recent winter I went from stock intake manifold to the Xcessive intake manifold. Went from 850cc side feeds to the 725cc top feeds, and went from a MBC to the Greddy EBC I now run. Prior to all that, I had no issues getting my car to idle "decently". I simply adjusted the injector latency w/ O2 sensing off until it idled, when up to temp, at approx 14.7:1.

I'm having a hard time getting it anywhere close to 14.7:1 with the new injectors, IM and EBC. Not that the EBC is really playing any part atm.

It wants to idle smoothest at roughly 10:1 AFR. When I adjust the injector latency to try and squeak it closer to 14.7:1 it starts to sputter and mildly backfire here and there. If I keep adjusting it to get it closer to 14.7:1 it will eventually get erratic and stall. When I hit the 12:1 range it seems like the AFR's like to jump up and down erratically, like, from 12:1 to 15:1.

I'm not quite sure how to go about getting this resolved. I'm going to check my plugs and replace my spark wires, but they didn't have issues with the prior setup. The other thing is that over the winter while getting worked on, it sat with about a quarter of a tank of gas in it (I forgot to fill it to the max), so I wonder if there is condensation in the gas tank causing the fuel mixture to be... "wet". I didn't dare drive it to the gas station the other day when I was trying to dial in the idle.

Once I do get the idle dialed in and am happy with it, i'm just curious as to how I should go about getting it tuned to drive for 2 straight hours to get it to the dyno. I mean... should I just run it really retarded/rich for that drive? My wastegate spring, I believe, is set for 7 psi and my BOV is set low too so that it can't really hit boost, and I don't plan on changing that until it's professionally tuned.

Any pointers/ideas of what I am doing wrong to get my idle set ok?

Any ideas of what I should do for the 2 hour drive to the dyno? I'd rather not have to trailer it, but if it comes down to it I can probably find a way to, though i'd rather not spend that kind of money.

Cheers folks!

[Matt]

went from stock intake manifold to the Xcessive intake manifold
Went from 850cc side feeds to the 725cc top feeds
went from a MBC to the Greddy EBC I now run

Prior to all that, I had no issues getting my car to idle "decently". I simply adjusted the injector latency w/ O2 sensing off until it idled, when up to temp, at approx 14.7:1.

The problem here is that you have only adjusted the latency for the injectors. The injection mutplier is the main one that needs changing here which is why it is still running overly rich

Put your ECU into closed loop (enable O2 sensors), clear your self learn trims and put latency to what the dead time for those 850CC injectors are advertised (at 14V)

Adjust your injection multiplier by ticking auto and pulling the value lower until your idle AFRs reach about 14.7:1 and your trims (FTS/FTL) return close to 0%. You can reset them again if required after adjusting K and try and get them about within 5% of 0

Have a look in the tuning training notes on our website for more info

After this when going on boost your AFRs should be reaching what you had previously when tuned (say around 11-12 range as a rough guide). Watch your trims dont move much from 0% and you should be good for driving to the dyno

The problem with tuning with the O2 sensor off by adjusting the multiplier and then reenabling O2 sensor, can result in your trims moving around afterwards in closed loop and adjusting your fueling from what you originally set

[Matt]

went from stock intake manifold to the Xcessive intake manifold
Went from 850cc side feeds to the 725cc top feeds
went from a MBC to the Greddy EBC I now run

Prior to all that, I had no issues getting my car to idle "decently". I simply adjusted the injector latency w/ O2 sensing off until it idled, when up to temp, at approx 14.7:1.

The problem here is that you have only adjusted the latency for the injectors. The injection mutplier is the main one that needs changing here which is why it is still running overly rich

Put your ECU into closed loop (enable O2 sensors), clear your self learn trims and put latency to what the dead time for those 850CC injectors are advertised (at 14V)

Adjust your injection multiplier by ticking auto and pulling the value lower until your idle AFRs reach about 14.7:1 and your trims (FTS/FTL) return close to 0%. You can reset them again if required after adjusting K and try and get them about within 5% of 0

Have a look in the tuning training notes on our website for more info

After this when going on boost your AFRs should be reaching what you had previously when tuned (say around 11-12 range as a rough guide). Watch your trims dont move much from 0% and you should be good for driving to the dyno

The problem with tuning with the O2 sensor off by adjusting the multiplier and then reenabling O2 sensor, can result in your trims moving around afterwards in closed loop and adjusting your fueling from what you originally set

[Sofa King]

Injection Multiplier is the k constant, correct? If so, i've tried adjusting that as well.

I was, however, tuning with O2 sensing OFF, so that could have something to do with it.

What are self learn trims and how do I clear them?

What is dead time? I'm running Injector Dynamics 725cc injectors currently and am unsure of why dead time of the old 850's matters.
ID's website shows "offset" for my injectors. It says at a fuel pressure of 43.5 and a voltage of 14 the "offset" should be set at 795. Is that injector latency?

What is FTS and FTL? I'm sorry to be so noob, but a lot of this didn't make much sense to me. I've read the PDF's and tuning guides from the site but it hasn't helped me much.

[Matt]

K constant = Injection multiplier
Watch the injection time gauge as you adjust this with 'auto' tickbox checked. It should increase injection time as K increases. AFR subsequently should go richer

You can turn off O2 sensing during adjusting K, but O2 feedback when reenabled may adjust fueling trims

Self learn trims are done by ECU monitoring the O2 sensor and adding/removing fuel trims (short term FTS/long term FTL) to adjust total injection time (see workshop training manual for more details)

Dead time = injection latency. So use 795uS for your latency figure

[Sofa King]

Ok. So here's where I am at now.

I've set my latency to 795uS @ 43.5 psi (fuel pressure). At this point, that should never be changed if I am understanding things correctly.

I've adjusted my k constant and gotten it to idle, when up to temp, at roughly 14.7 w/ o2 sensing ON. It fluctuates between ~14.3 and 15. I think that seems to happen when the current cell of MAF Voltage Quantifier changes between one cell and the one next to it.

So, at this point I feel good about how it idles. It's still a little rough feeling, but the AFR's seem to be where they should be.

Now, it's to my understanding after reading the workshop that Alpha N mode flag should just be disabled, since I do not have VE maps and my car is turbo charged.

So if I understood you correctly, I need to now keep O2 sensing enabled, turn on the O2 Sensor Analysis flag, turn Long Term Trim flag on, and try to get the trims within 5% of 0 while idling at ~14.7 ?

When driving it do I continue to keep O2 sensing enabled? At this point It's not very easy to get it into boost when driving normally (following speed limits, not aggressively accelerating).

Cheers!

[Matt]

You are driving on NA fuel maps at the moment, so it wont hurt to increase the fueling up the top end to about the 11:1 mark for now

Increase K constant a little so your AFRs are richer than 14.7:1

Yes you can turn o2 sensing back on. AlphaN flag needs to go off since it is now turbo charged so volumetric efficiency points in the AF AlphaN table (using the last column of the fuel map against TPS voltage) are not the same any more

[Sofa King]

Out of curiosity, should I have started this whole process with the stock MT bin file like I did, or gotten a pre-made bin much closer to my needs for my setup?

KA-T forum hosts bins and some users have suggested getting one close to my setup and adjusting the settings to fit my needs.

I downloaded a 750cc injector Z32 mafs bin (I run 725cc and a Z32 mafs) which is damn close.

I ran into a problem though. Whenever I try to load that bin (or ANY bin from the forums for that matter), the car/engine that it automatically tries to use is a Pulsar SR20DET bin....this makes me think I am doing something wrong. The following is the exact message I get.

"ECU Image/Address file mismatch

Current address file: S13 240SX KA24DE

File from ECU: RNN14 Pulsar GTIR SR20DET (54C00)
Found address file: RNN14_SR20DET_256_E.adr

Auto load this file?"

At this point Nistune forces me to load that address file in order to use the bin that was hosted in KA-T. This doesn't work, because the car won't sync with my laptop if the SR20DET address file is selected. Then, if I select the S13 240SX KA24DE address file, all of the info from the hosted bin is gone, thus, making it pointless.

Is this a bug? No-one has been able to tell me what's going on yet. I hope you can lol. The same bins I am downloading from those forums do not seem to do this for other users.

Cheers.


EDIT: I just installed Nistune on my desktop and downloaded the desired bin file from the forums. I get the same error on my desktop as I do on my laptop.

[Matt]

I downloaded a 750cc injector Z32 mafs bin (I run 725cc and a Z32 mafs) which is damn close.

Someone had a pulsar base image loaded, and then synced the S14 maps over the top of it

Load a factory S14 image under Main. Then open in the comparison this downloaded file.

Use compare icon (magnifying glass) to see which maps are different from stock. Review them
Use COPY icon and copy only the main fuel, timing maps, scalers, MAF and injection latency and multiplier across, plus any other maps you want to copy across (like limiters etc)