NGC3 Attempting to tune off fuel trims - trims going nuts

Having a hard time tuning off of the LT & ST fuel trims. I am not well versed in Dodge tuning, but have experience with GM & Ford. It seems like trying to tune using the narrowbands in this car is about pointless, there are random bank to bank discrepancies, in addition to the two biggest issues I'm facing below:

Issue 1: At idle the NB sensors are pinned rich, yet the trims are holding a positive value. Why are the NB sensors not responding to the rich condition and trimming fuel out to get to the switch point? In the snip below the total trim is +10% and the NB voltages are 882 & 822mv - and it will hang this way for as long as 10 minutes (at which point I give up).
Attachment 105182

Issue 2: Somewhere around P Ratio .8 to 1.0 at part throttle the LTFT start swinging 30% or more. For example, if they are holding a +15% they will start radically swinging as far as -20% and back to +15% over and over and over. It is so dramatic you can feel it in the car big time.
Attachment 105183

This is a customer car:
2005 Dodge Magnum
5.7 w/ Procharger & blower cam
Headers & full exhaust
80# injectors

Attachment 105184

Quote:

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Originally Posted by Nickg124

Having a hard time tuning off of the LT & ST fuel trims. I am not well versed in Dodge tuning, but have experience with GM & Ford. It seems like trying to tune using the narrowbands in this car is about pointless, there are random bank to bank discrepancies, in addition to the two biggest issues I'm facing below:

Issue 1: At idle the NB sensors are pinned rich, yet the trims are holding a positive value. Why are the NB sensors not responding to the rich condition and trimming fuel out to get to the switch point? In the snip below the total trim is +10% and the NB voltages are 882 & 822mv - and it will hang this way for as long as 10 minutes (at which point I give up).
Attachment 105182

Issue 2: Somewhere around P Ratio .8 to 1.0 at part throttle the LTFT start swinging 30% or more. For example, if they are holding a +15% they will start radically swinging as far as -20% and back to +15% over and over and over. It is so dramatic you can feel it in the car big time.
Attachment 105183

This is a customer car:
2005 Dodge Magnum
5.7 w/ Procharger & blower cam
Headers & full exhaust
80# injectors

Attachment 105184

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For issue # 1, check to see that your idle injector PW isn't getting too close to your "Min Inj PW" setting in the fuel tab. I had this issue with a Neon SRT-4 that would do exactly as you described, and even though my idle PW wasn't technically reaching the "Min Inj PW" value (it seemed to always be at least 0.2 ms over the Min value at idle), it would prevent STFT from responding (they'd stick positive if they were in the positive on the way down to idle).

Issue # 2 has plagued my 06 Jeep SRT-8 for quite some time as well. I still haven't found a solution for it. Some folks will recommend messing with the transport delay table, but I've not found this to decrease the amplitude of the fluctuation, only the frequency. I know that in a competitor's tuning software, there is a VE correction vs o2 sensor voltage table that we don't have in HP Tuners software. I feel like that table could be very helpful in this situation, but requesting it to be defined via HPTuners Support ended up falling on deaf ears, unless I'm able to provide the address of said table, which I don't have and don't know how to get.

Here's a screenshot of the tables I'm referring to.

Attachment 105197

My opinion....look at the min pw for idle.
the part throttle problem ca be the blowoff valve, maybe you got too much air in.

I would check the map sensor output. I know that the ecm in the 2005 is different from my 01 Cherokee but I have had problems like that after writing a new tune. The map sensor would give a false reading and make the fuel trims go crazy then peg rich. In my case all I had to do was disconnect the battery and then the sensor would work correctly again and the engine would operate fine.