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?