I decided to experiment with the Vec3 IAT today on my n.a. '01 RT/10. I originally set a 10% fuel correction between 90 & 115 degrees so that fuel would begin to be subtracted between 90 and 115 degrees as a start. I've been running rich during open loop and just got my AFR closer to normal but with heat and multiple pulls today the PCM was fighting me at these higher temps and making the car run richer during WOT. During my logging, I saw fuel being added by the PCM as the temperatures began to hover over 90 up to 120.
After I wrote the change the Vec3 and started my car, my AFR during idle hit 17 and hovered between 16.5 and 17 and up to 18 as I drove about 50 feet. The car ran horrible so I shut it off. I then shut off the IAT feature in the Vec and idle was back between 14.7 and 15.5.
I tried the IAT feature again except this time increasing the minimum temperature to 105 degrees and did a conservative 2% adjustment and the AFR was back to normal during closed loop. In fact, it was a bit richer and closer to 14.7 than it has been in the past. In my logs, I can see that the IAT was working during my pulls and helped keep my AFR steady in the higher temps. As a sanity check, I tried a lower temperature setting and lean behavior occurred again during idle.
I can see that the IAT was also working during closed loop because my logs show IAT fuel corrections in this mode. It seems that the IAT feature works continuously in both CLOSED and OPEN loop? Is this correct? I was pleasantly surprised by this as I always assumed it was an OPEN loop operation for some reason.
- Tony
After I wrote the change the Vec3 and started my car, my AFR during idle hit 17 and hovered between 16.5 and 17 and up to 18 as I drove about 50 feet. The car ran horrible so I shut it off. I then shut off the IAT feature in the Vec and idle was back between 14.7 and 15.5.
I tried the IAT feature again except this time increasing the minimum temperature to 105 degrees and did a conservative 2% adjustment and the AFR was back to normal during closed loop. In fact, it was a bit richer and closer to 14.7 than it has been in the past. In my logs, I can see that the IAT was working during my pulls and helped keep my AFR steady in the higher temps. As a sanity check, I tried a lower temperature setting and lean behavior occurred again during idle.
I can see that the IAT was also working during closed loop because my logs show IAT fuel corrections in this mode. It seems that the IAT feature works continuously in both CLOSED and OPEN loop? Is this correct? I was pleasantly surprised by this as I always assumed it was an OPEN loop operation for some reason.
- Tony
