S300 datalog review - hesitation

[93h22a]

I am new to this forum and hoping I am putting this message in the right area of the forum, if not my apologies.

I have been researching information high and low and even had work done on my car and I still cannot nail down the hesitation that comes and goes.

Background:
My 93 Honda Prelude H22A received a makeover this past summer. For purposes of this forum here is the engine work that was done.
AEM cold air intake
APEXi WS2 Exhaust
PLM header and custom high flow cat
P72 ECU - Dyno Tuned
Hondata S300

The car had hesistation prior to the work however it did not clear even after a new ECU and tuning. I recently had a leak down test down and vaccums verified and mechanically the engine is tight and all is good. Even had throttle body removed and cleaned and new TPS put on.

Current issue:
The car runs great other than the hesitation around/between 2.5 to 3.75 RPM. Interesting enough that when it does occur and you stay in that range it doesn't stop with the hesitation but you throttle down and she snaps out of it. It doesn't do it all the time and can change from stop light to stop light. Its like the RPM will continue to rise but there is no power being produced.

I am hoping that with these data logssomeone could spot something out of the ordinary that might lead to the issue.

Some information on the datalogs.

The first datalog (file1) is a 20 minute drive through town just like I would normally drive it.

In this file around the time of 5:51, 12:58 and 13:58 i was able to feel the hesitation pretty good. At around 18:40 I was driving in 3rd gear with low throttle and you could feel a slight "swaying" while maintaining a steady speed.

In the second datalog (file2) it was about a 10 minute run. At about 2:50 I ran a 3rd gear 2K RPM WOT to red line. I did this again at around 6:30.

The one thing that stood out to me was the Injector voltage (i believe that is what it is). It seems that it is "wavy" as apposed to some of the other data points that I seen.

Additional note, I can repeatedly hold the car about 1800-2000 RPM while standing still and the idle will drop out and then bounce back to 1800-2000 and drop out again. It will do this for as long as I hold the RPM in that range. Anything above or below and it maintains proper throttle. This can be repeated on demand at anytime.

I apprecaite anyones time and input on the situation.

Thank you, Anthony

[Spunkster]

You have not posted the calibration.

[93h22a]

Spunkster,
Can you help me out with that? New to the software so not sure how to pull that from the ECU and save it to upload?

[Spunkster]

What is the serial number of your s300?

[93h22a]

Spunkster,
Found the download calibration however the location is grayed out and cannot be changed from the tune shop.

serial number registered is 2261

[Spunkster]

Before doing anything else you should try to contact whoever tuned this originally and have them email you the calibraiton, because if you corrupt the calibration on the ECU you will not have any backup.

[93h22a]

Well i had sent him the datalogs and yet to hear from him which is why I started doing some research on my own hoping to get someone else to review them and maybe see an anomaly.

I thought maybe you could pull the uploaded file from Hondata since it was uploaded at registration, which is why you asked for the serial?

Why would I not be able to pull it down from the ECU myself if it is not password protected and everything is registered to me? Is there a certain location on the computer Hondata will download the file to and I am just missing it? There are no errors when I hit the download button, basically I see nothing happen...

So the datalogs cannot be reviewed with having the calibration file?

Thanks for your help on this, I do appreciate it.

[allm0t0rGSR]

this happened to me today and the other day, the motor sound like missfiring and my wideband showed really rich like it goes to 11:1 afr it only happen between 2k to 3k rpm... i dont have any datalog for now but i will.... this start happening when i updated to 2.2.4 beta vers.

new distributor
new spark plug (gap at 0.35") ngk bk7re
new spark plug wires

[93h22a]

Hey Spunkster, figured out how to save calibration. Learning more and more about this software.

Thanks for the time and info.

[Spunkster]

Your short term fuel trims are going nuts at times. Without a wideband it is hard to tell exactly what is happening.

[93h22a]

Thanks Spunkster for the review. I see what you are talking about on the S.trim. I also noticed the TPS min/max was not set correctly after a new one was put on. Even though it acted this way before i changed the TPS i went ahead and reset min/max and that really cleared up the throttle response on the higher peddle.

Not sure when I will be able to get the wideband installed but it is a good direction.

Actually I was driving it after the TPS adjustment and it felt good and thought all was well and it started "its thing again". I had the laptop hooked up and hit record as soon as i started feeling it.

It is only a 4 minute run but you can see the s.trim going crazy at the start of the file and I think that confirms your input.

Is there anyway to "clean that up" without a wideband sensor? I know it was dyno WOT and from what I have been reading that is not bad but does not help with day to day normal driving.

[Spunkster]

Part throttle tuning is just as important if not more inportant that WOT tuning as about 97% or more of driving is done at part throttle.

[93h22a]

I am new to this arena of tuning, so can you do part throttle tuning without the wideband sensor?

[Spunkster]

To do any tuning you need a wideband.

[93h22a]

Bump on this topic as it still exists but found new info.

I talked to the guy that tuned the car and we did some testing. I switched it to open loop and all the hesitation and stuff has gone away. I have ran that way for a couple months now but notice that it does not have the response that it gets when running closed loop-stock sensor.

He did tell me that he does a full mapping and it is not just WOT tuned.

I have read around that it is good to tune with wideband but then go back to closed loop and let the ECU do its thing. Thoughts on this?

I put the car back in closed loop today and it felt good to drive it (not that open is terrible) but that hesitation occurs and from all the reading I'm doing I'm feaful i might be running lean but then again I don't know what is considered lean as I'm not overly familiar with engine's at this level.

So couple questions -
If running open clears the issue is it assumed that the o2 sensor could be bad even though it was replaced when it was tuned and exhaust was put on?

Is it possible that the wires running from o2 sensor to ECU are faulty and maybe grounding or something?

Any other insights to the issue since it seems to run fine in open but in closed it creates some hesitation around the 2.75 to 4k RPM range when running steady throttle? Lower RPM and WOT and it "snaps out of it" in closed loop.

Spunkster - I know you like seeing datalogs and I have uploaded them in this topic, hopefully all is there that you need. Nothing has changed on the tune since then but I can run more if you need them.

I appreciate the time and information.