ANN Tuning IPW having no efect.

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05-09-2019
WS6HUMMER

2 Attachment(s)

ANN Tuning IPW having no efect.

I don't usually tune with the ANN on but in this case the vehicle will go from sea level to 14,000 feet elevation so I thought it would be better left on. This is also a Hemi swap with some kind of hybrid modification to the PCM, it's a 3.8L jeep pcm. So the problem is that I feel like I'm trying to shoot a moving target, I cant ever get target AFR and measured AFR to line up, having a rich tip in & lean spike. I have the COT F/A enrich off if anyone was thinking about that, I've also tried spreading the WOT fuel mas resolution as well and still no dice. Anyone ever run into this? I thought maybe the IPW offset was wrong for the injectors it has but I got the number off them and compared it to another 5.7 Ive tuned with the same injector and all that is good. :banghead:
05-20-2019
WS6HUMMER

No one has had this happen before? It looks like the issue is mainly around the pulsewidth where it's making peak torque so I'm going to input a pressure transducer and log the fuel pressure. Kinda at a loss for any other ideas at this point.
05-20-2019
Blue Bee

Tuning in VE you have all the same baro multipliers and things going on, you don't have to be in NN for the elevation worries. I think with the resolution you have given yourself in PW, you will be chasing you tail forever. Kind of defeating the linear effect the injector should have by so many points. i will give my self points to a certain extent and leave them and mess with fuel mass. But that's just me.
05-20-2019
WS6HUMMER

Quote:

Originally Posted by Blue Bee

Tuning in VE you have all the same baro multipliers and things going on, you don't have to be in NN for the elevation worries. I think with the resolution you have given yourself in PW, you will be chasing you tail forever. Kind of defeating the linear effect the injector should have by so many points. i will give my self points to a certain extent and leave them and mess with fuel mass. But that's just me.

Thank you for the advice, I'm to the point of going that route but just wanted someone's input in case I was missing something. I'm gonna make a pull with the fuel pressure logged and if it's good off goes the ANN.
05-20-2019
lafrad

Why does your fuel injector PW go "DOWN" in the bottom cells?
You really want that to be going up all the way across the scale, and you really REALLY should have something out in the 25-30ms range, as this will cover transient events at low RPM..... If the highest value you have for fuel mass in that table is 16ms, it has no idea how to get the fuel it needs for aggressive tip in (and the like)
05-20-2019
Blue Bee

Quote:

Originally Posted by lafrad

Why does your fuel injector PW go "DOWN" in the bottom cells?
You really want that to be going up all the way across the scale, and you really REALLY should have something out in the 25-30ms range, as this will cover transient events at low RPM..... If the highest value you have for fuel mass in that table is 16ms, it has no idea how to get the fuel it needs for aggressive tip in (and the like)

Yea, I just looked at his pic, you need to fix that bottom cell at 12.7ms...FIRST, make it 25ms to be safe and bump fuel mass some. Really you don't need higher than 20ms that is past 100% DC. If you need more than 16ms on tip in something is wrong for sure!
05-21-2019
timskmperf

idk if this is what you mean. but i spent an entire day chasing my tail messing with these tables and had forgot to 0 out my Pratio and Aircharge tables becuase its a multiplyer... every change i made to these tables didnt help me at all.
05-21-2019
WS6HUMMER

Quote:

Originally Posted by Blue Bee

Yea, I just looked at his pic, you need to fix that bottom cell at 12.7ms...FIRST, make it 25ms to be safe and bump fuel mass some. Really you don't need higher than 20ms that is past 100% DC. If you need more than 16ms on tip in something is wrong for sure!

That's the problem, it was lean in the same spot no mater what the IPW, I tried many different things and couldn't satisfy the lean spot at the same fuel mass. Fuel pressure was rock solid so took it off the ANN and now the fuel is dead on. Ive tuned with the ANN on a few times with pretty good results although it's not my preference to tune that way, I guess in this case I either missed something or it was something weird going on with this hybrid situation with the V8 OS and v6 computer.
05-21-2019
richhurley

1 Attachment(s)

The way I do it is to create graph that logs the LTFT+STFT % error vs. the Fuel Mass values in the InjPW vs FM table. Do some data logging and when that table populates, take the values from that table and paste special back in the InjPW/FM table. Don't forget to make the change to the inverse table.

Attachment 89981
05-21-2019
WS6HUMMER

Quote:

Originally Posted by richhurley

The way I do it is to create graph that logs the LTFT+STFT % error vs. the Fuel Mass values in the InjPW vs FM table. Do some data logging and when that table populates, take the values from that table and paste special back in the InjPW/FM table. Don't forget to make the change to the inverse table.

Attachment 89981

That won't work for WOT, that's the area I had the issue at.