The tune runs differently when burnt to a chip

Reply to topic
    Reply with quote

The tune runs differently when burnt to a chip

shiftyjonno Tue Aug 02, 2016 1:31 am

I've come across an issue where the tune on the chip behaves differently to the same tune on the Moates Demon.

I tuned a modified b18c on a Mustang Dyno using a JDM P72 (SMD type), Moates Demon and LM-2 serial logging.
The tune went well with no issues, it felt good the A/F's were right where they should be. The owner was with me and confirmed they were happy with the tune.
After the dyno, I burnt the tune to a chip and installed it in a socketed PR3 (through-hole component type) as per normal.

The owner then installed their own wideband O2 sensor, and contacted me to advise that they are experiencing problems with a lean idle, and rich at cruising. I wasn't sure of their electrical knowledge or capability, and so my first thought was that the O2 sensor wiring or install has been mucked up somehow and was giving an odd reading.

I then installed my LM-2 wideband to check the owners claims ... sure enough, it was running lean at idle and rich at cruising ... this was definitely NOT the same tune that I did on the dyno.

My next thought was that there was a difference between ECU's ... The JDM has surface mount components and the PR3 has through-hole components.
So I installed my Moates Demon directly into the owners PR3 ECU to make the necessary changes and rule out a difference in ECU as the cause of the fueling gremlins.
We went for a drive and identified the problems and made the necessary changes to the tune.

We BOTH saw the A/F's at idle (14.5:1) and BOTH agreed that we were happy with the new changes, so I saved the tune to a .bin (as per normal) and burnt it to a chip .... within a 5 minute period the new tune was installed in the same ECU I had just made changes with.

Well bugger me ... the A/F's had gone lean at idle (16.2:1) and after a couple minutes settled down to 15.4:1 at idle. We BOTH saw and agreed that this is NOT what I tuned and NOT what I saved ...

It is the first time I've come across this issue and so I spent a fair bit of time trying different combinations to work out what exactly caused it.
Somewhere between the Demon, saving the tune, burning to a chip, something has changed the behaviour of the tune ...

Does anyone have any idea what it could be?

shiftyjonno

 
Posts: 7
Joined: 31 Jan 2011
    Send private message View user's profile

    Reply with quote

HRTuning Tue Aug 02, 2016 2:11 am

Did you try on the Demon without the laptop connected?

_________________
Like us on Facebook.
http://www.facebook.com/NepTuneEngineManagement

HRTuning

 
Posts: 10145
Joined: 05 Sep 2004
Location: Phoenix, AZ
    Send private message View user's profile Visit poster's website AIM Address

    Reply with quote

shiftyjonno Tue Aug 02, 2016 11:13 pm

HRTuning wrote:Did you try on the Demon without the laptop connected?


Only for a short period of time after I saved the tune. I then disconnected the Demon from Neptune, but it was still plugged in to the laptop ...

Would it make any difference?

What are your thoughts?

shiftyjonno

 
Posts: 7
Joined: 31 Jan 2011
    Send private message View user's profile

    Reply with quote

HRTuning Tue Aug 02, 2016 11:24 pm

If the ECU is not receiving solid voltage it's possible you're backfeeding it some voltage through the USB/Demon. This could effect operation.

_________________
Like us on Facebook.
http://www.facebook.com/NepTuneEngineManagement

HRTuning

 
Posts: 10145
Joined: 05 Sep 2004
Location: Phoenix, AZ
    Send private message View user's profile Visit poster's website AIM Address

    Reply with quote

shiftyjonno Tue Aug 02, 2016 11:35 pm

HRTuning wrote:If the ECU is not receiving solid voltage it's possible you're backfeeding it some voltage through the USB/Demon. This could effect operation.


From what I observed on Neptune while I was checking the battery offset table was that the voltage appeared to be fine and solid. Voltage would drop to 12.5v under high load (high beams on, aircon on, all power window buttons held on). After minor battery offset adjustment the a/f's were solid under any varied electrical loading.

The laptop was running off battery at the time ... if that makes any difference.

How does one monitor the voltage to the Demon?
Are there any other likely causes?

shiftyjonno

 
Posts: 7
Joined: 31 Jan 2011
    Send private message View user's profile

    Reply with quote

HRTuning Tue Aug 02, 2016 11:41 pm

None I can think of.

_________________
Like us on Facebook.
http://www.facebook.com/NepTuneEngineManagement

HRTuning

 
Posts: 10145
Joined: 05 Sep 2004
Location: Phoenix, AZ
    Send private message View user's profile Visit poster's website AIM Address

    Reply with quote

shiftyjonno Tue Aug 02, 2016 11:53 pm

HRTuning wrote:None I can think of.


Odd ... could the Demon battery be the culprit?

Thank you for your quick responses. Awesome customer service as always Smile

shiftyjonno

 
Posts: 7
Joined: 31 Jan 2011
    Send private message View user's profile

    Reply with quote

HRTuning Wed Aug 03, 2016 12:37 pm

Not likely. The Demon battery is only used for backup. When powered by USB or the ECU itself that's where it's sourcing power. Try removing USB and see if it has any effect with Demon.

_________________
Like us on Facebook.
http://www.facebook.com/NepTuneEngineManagement

HRTuning

 
Posts: 10145
Joined: 05 Sep 2004
Location: Phoenix, AZ
    Send private message View user's profile Visit poster's website AIM Address

    Reply with quote

shiftyjonno Wed Aug 03, 2016 8:42 pm

HRTuning wrote:Not likely. The Demon battery is only used for backup. When powered by USB or the ECU itself that's where it's sourcing power. Try removing USB and see if it has any effect with Demon.


Sure thing.

Thanks for the quick responses and top notch customer service Smile

shiftyjonno

 
Posts: 7
Joined: 31 Jan 2011
    Send private message View user's profile

    Reply with quote

HRTuning Wed Aug 03, 2016 10:00 pm

Very Happy

_________________
Like us on Facebook.
http://www.facebook.com/NepTuneEngineManagement

HRTuning

 
Posts: 10145
Joined: 05 Sep 2004
Location: Phoenix, AZ
    Send private message View user's profile Visit poster's website AIM Address

    Reply with quote

jesse888 Sun Oct 29, 2017 7:43 pm

hi guys.
new here but im having the same problem.
tuning via ostrich, burn a chip and the tune behaves as if the injector deadtimes are off and runs lean on idle and low load conditions. runs perfect off the emulator though...

jesse888

 
Posts: 1
Joined: 29 Oct 2017
    Send private message View user's profile


Reply to topic

NepTune Chip Based Questions/Comments

 

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum