Hondata

S2000
Kmanager 4.1.1
F20C stroked to 2.4L
ITBS on Alpha N

Problem occurs at 4:32 and ends at 4:46. My INJ was 0.00ms for the entire time. You can see from the log that I tried to jab the throttle (both in and out of gear) to exit what I thought may have been an overrun condition, but it didn't work. At 4:44, my engine completely stopped because I was out of gear, but since I was still rolling, I put it back in gear to start the motor. After I did that, it seems that the problem was fixed.

http://www.hondata.com/forum/viewtopic.php?t=13940

This sounds like a similar problem to what I have. Anyone know how I can resolve it?

I did some more testing and tried the following, but was still able to recreate the issue regardless:

I made a brand new one map and erased the ECU before uploading.
I changed the overrun cutoff settings to be higher than the Alpha N map value when throttle fully closed.
Tried to have fuel over-run delay both enabled and disabled.
Tried IACV enabled and disabled.
Messed around with VTEC window boundaries.

Every time I'm able to recreate the issue, I have to let the RPM drop all the way to 0 before putting it in gear to restart the motor.

I tried making a speed density map instead of a Alpha N map. Both the calibration and log files are attached. Excuse the poor tune.

INJ went to 0ms at 1:43 of the log and stayed that way until 2:01 when I let it just stall out. During that period, I used the throttle multiple times but INJ stayed at 0ms. I previously suspected it could be a MAP issue, but the Map sensor still read correctly when the was car stalling out.

I also just tried to revert to KManager 3.3.0 since I never encountered this issue prior to this month and updating to the newer KManager. I've been using my Kpro for at least 4 years and I've had my stroked F20 with ITB for the last two.

Based on the data in the logs, I'm 99% sure it's an issue with the KPro or tune. Is it possible that it's something else on the car?

Is it possible that my Kpro is dead? If I pay for the V4 upgrade from V2, will this resolve my issue?

Hi Ronac,

It was a problem on my Chasebays cm2 milspec harness which had the signal for the map and tps reversed.

What harness are you on?

I'm using a stock harness with a couple things extended. I've been running this configuration for months before this problem arose. Both the map and tps signals read fine in the catalog when the fuel cut out.

I also tried physically adjusting the tps to be much closer to 0 (+0.4%) instead of -2.2%. I was still able to recreate the issue. Seems like every time I let it stay in overrun for too long, it can't exit out of it.

You may need a vacuum accumulator as it could be related how it is reading vacuum. Your overrun cutoff values do look a little unusual as well. You might want to try values higher than zero.

I do have a vacuum manifold setup.

What do you suggest I try for the first overrun settings? Since my tune is alpha n, I need overrun to end as soon as I get on the throttle.

Can you elaborate a bit more about what is wrong with the vacuum readings?

Hi HONDATA, do you think you can chime in on my issue? I have a lengthy chat with Spunkster on the phone but we didn't come up with very many ideas.

Also, would you be able to elaborate more on how the overrun settings work for Alpha N since it's a MAP value you enter?

Your overrun cutoff values are 0. I would make these less than 10 kPa, but not zero.
Closed loop is enabled but the o2 sensor is not working and the o2 heater has an error disabled. Either run in open loop or fix the o2 sensor.
Fuel overrun cut delay is disabled. Try enabling this.
Set the tip in gear retard multiplier to -100 for all gears.
One thing which is it not possible to tell from any datalog is how well the MAP sensor is reading manifold pressure. With ITBs it is not going to be perfect, but it needs to read close to reality for the ECU to work correctly. I believe this is the problem, but try the changes above first.

Every time I click "Disabled (Open Loop)" for close looped operation and try to save the KAL, it reverts back to "Narrowband (Secondary Oxygen Sensor) -PRA". Is this supposed to happen or is this a bug?

No, it is a bug, which has been fixed now.

I made those changes you suggested and I think the issue is gone.

I added some more restriction to the IACV to bring the MAP reading to be closer to a non ITB car. I think that's probably what solved the issue. Thanks for the insight on how the overrun works. On that note, when you're on Alpha N, is there a way to log the actual MAP reading?

In regards to the software bug, I'm guessing it'll be fixed in the next version, 4.1.2? I also noticed that the idle control settings seem to get blanked out when I have the Kmanager connected to the KPro. Is that a bug as well? Or are those settings for KPro V4 only?