Nistune Forums

I'm getting misfires under part throttle (~70% or 3.3VTPS) because my AFR is too rich (9:1 etc.) under that same cell though during WOT I'm too lean (13.5:1).

This is happening in a cluster of cells.

I've tried spitting the columns, but the ECU accesses list the same TP during both so it accesses the same cell.

Help.

Log of problem and BIN file please

I have a NA ka24de with a n60 maf and 380cc injectors. Car drives great during idle and wide-open throttle and pretty much everywhere except ~4800-5200rpm's under 70% throttle or so, that's where it misfires.

You can see it happen @ 6m57s and 10m36s or so in the log and a few other places.

I also have a KA24DE and checked out your bin...
Are you actually running this as it appears?

Yes, but keep in mind the Target AFR map view isn't accurate, and I believe no one really uses it to tune.

modulation wrote:Yes, but keep in mind the Target AFR map view isn't accurate, and I believe no one really uses it to tune.

How true is that? When you say, isn't accurate, do you mean that the values shown on there are what the ECU aims for, but the AFR's at the back are different, or do you mean, the values in there are NOT what the ECU is aiming for???

Start over. That looks like a broken engine waiting to happen.
Disconnect your o2 sensor.
Select the flags box in the bottom of the fuel map. The closed loop area will now highlight. Change all non highlighted areas of the map to a 12.5 or richer afr. Ensure all the knock/gear maps are the same or change them radically to a 7.5 afr so you can tell when you switch to them. Go for a ride and see how close the reported afr's are to the commanded afr's. (BE CAUTIOUS) Adjust K value for higher load/rpm afr's, adjust latency for lower load/rpm afr's.

Things to note; ensure engine is fully warmed before tuning. Ensure ttp min table is zero'd, and ttp max is 255. Making the adjustments to the K and Latency can take a while so don't expect to get it perfect in 1 or 2 attempts.

HermaN wrote:

modulation wrote:Yes, but keep in mind the Target AFR map view isn't accurate, and I believe no one really uses it to tune.

How true is that? When you say, isn't accurate, do you mean that the values shown on there are what the ECU aims for, but the AFR's at the back are different, or do you mean, the values in there are NOT what the ECU is aiming for???

Those AFR values are roughly calculated in the software and have nothing to do with the ECU. The ECU only uses the raw values from that table which tell it the pulse-width.
Even when I had a 100% stock ka24de and nistune those numbers were still way off.
Look at the general nistune guide and mapping guide, they never use AFR view to tune, they use raw/filter.

Keep in mind I don't have a stock maf or stock injectors.
Here are some sources about the Target A/F view being non-accurate. I can find more if you'd like:

viewtopic.php?f=12&t=849&hilit=target+a%2Ff
Matt says "the target AFRs are purely theoretical and are subject to change after MAF and injector resizing substantially. they are good to get an idea, but a lot of people use filtered values and monitor the output AFRs"

In this thread, there is a post by Matt where he says "I have in my 'problems' list an item to make the target AFR display adjustable so it more closely reflects what the actual AFRs are so it displays
properly." (Don't believe he got around it it, because it's low priority.)
viewtopic.php?f=7&t=1162&start=0&hilit=target+a%2Ff

Bernardd wrote:Start over. That looks like a broken engine waiting to happen.

Do you base that off the AFR's or something else?

modulation wrote:

Bernardd wrote:Start over. That looks like a broken engine waiting to happen.

Do you base that off the AFR's or something else?

Your at WOT and running 13.5 AFR, that's not being kind to your motor at all.

Adam wrote:

modulation wrote:

Bernardd wrote:Start over. That looks like a broken engine waiting to happen.

Do you base that off the AFR's or something else?

Your at WOT and running 13.5 AFR, that's not being kind to your motor at all.

I'm NA though so 13.5:1 while higher then I'd like is no where near danger zone.
13.5:1 is also a bit of a exaggeration its more like 13.2-3

I think my K constant was too high. I set it from 30,750 to 30,000 and increased fuel in some places and it seems much happier now.
Sill a bit more rich under 80% throttle then WOT, but that's ok.

if you do an AFR trace throughout several runs, what does that look like? Its the end AFRs which are important.

Also your fuel map should be nice and smooth. Bumps etc will cause issues with the interpolation between cells

The bin I posted above appears to be corrupt. When I download it in nistune again, the fuel cell values are all wrong.
Is that because it was created/saved using a older address file, and I'm using the current one to open it?