Trying to set Air Flow Through Throttle body in Advantage III

[04torchred]

So I have been having some issues with getting my car to idle.

Newly added mods to my motor are a crusher inlet on my 3.4, VMP big TB and ID1000's.

To get it to start and not drop rpms and die I had to unhook the IAC, open up my Throttle blade until it would idle on its own with no throttle input at 750-800rpm. shut car off and reset my TPS. Started the car and hooked my IAC back up and idle went up around 300rpm to sit at 1100-1150 range. during all this my ISC duty cycle never dropped below 0.5-0.54.

So I think I need to adjust my Airflow Through Throttle body number from the stock 0.334 #/min to a new value.

Here is my question. I found the MAF #/min PID in livelink and datalogged that at idle with the IAC unhooked. The value I recorded was 373.022 #/min. This doesn't make sense as PRP only accepts a value for this of 0-2.

Is that value I logged of 373 suppose to be 0.373? Not sure why the PID value is off from the software.

I am kind of lost. After I fix this value in the tune I think the only other item I can adjust is ISC neutral idle air table.

 

[decipha]

first off, SCT is ancient for tuning any EEC, 10 years ago moates came out with a realtime emulator for the eec-iv and eec-v that basically turns your eec into an aftermarket standalone with realtime tuning and far superior datalogging
go to moates.net and get yourself a quarterhorse, you will thank me later


the reason why the idle is kicking up when the iac is plugged back in is cuz the duty cycle is so high

at a warm stable idle you want the isc duty cycle below 35%, ideally 10% is perfect which is basically off

set the throttle body airflow scalar to 0, set the isckam update rate to 255 to disable it, then be sure to clear the KAMs

go to the fn875 idle air neutral function and set the entire y axis to 1.0, you can 0 out all the rpm values other than the top value of 16384 but not neccessary

go to your isc multiplier table fn1862 and adjust those values to get IPSIBR to stay as close to 0.000 as you can get it from cold start to warm idle

logging with SCT and doing the log, adjust, save, upload to handheld, flash to ecu method, then re-log and adjust again just to repeat the process takes several hours, with the quarterhorse you can dial it in 10 minutes making realtime changes while the engine is running and seeing the results immediately

 

[04torchred]

Thanks decipha, is what your suggesting to do only valid for a strategy in QH. Right now switching tuning platforms isn't in the cards, but maybe down the road. I do agree with you the load a tune go test it and log it, back in the house tune it... rinse repeat shit is slow.

So my ISC neutral idle air table is off? Do I understand that correctly?

And now that I have opened the throttle blade to add additional air my IAC valve is still being commanded to add more air then needed due to 1. my Airflow through TB value is incorrect due to the increased blade opening and 2. my ISC Neutral Idle Air table with DsdRPM and Air_#/min is asking for too much air.

The computer determines the air amount by using the DsdRPM(Air_#/min) value - Airflow Through TB value(stock for this is 0.334 in my tune file under AMZ2.

So if dsdrpm is 800 table shows 1.6489 on my current .mtf file - 0.334 = 1.3149 #/min of air(which in my case is too much and causing the high idle issue and big duty cycle?

Am I following the logic of how it determines the speed at which to idle?

 

[decipha]

yep thats it, fn875-ithbma (tb flow) is thn multiplies by the isc multiplier table fn1862

all the details and the logic are in my idle air write up on my website

http://www.efidynotuning.com

click on write ups in the top menu and then click on idle air and it will give u all the info u need

my apologies for the delay i dont frequent here often