nickel417

I have a 04 GT with minor bolt ons and have been using an IAC restrictor plate to help in making my RPMs drop faster and idle quicker but have gotten tired of the car idling too low and putting a drain on battery with the AC on at idle so I put the IAC gasket back to stock. I have the commando tuning software so all tuning parameters are available to me.

What parameter should I work with to make the car decel better and have rpms drop quicker. Also what parameter should I work with to keep the idle from hanging at 1500 rpms for about 5 - 10 seconds when coming to a complete stop?

Any help will be appreciated

cliffyk

What is your box code? I will look at your tune's template and see what is available...

nickel417

Computer code on my car is RKN2. Thanks in advance for any help

cliffyk

I wanted to make sure it was similar to my '03. You want to alter the LB/MIN Airflow values in the Dashpot Settings function, here are the values I run:



Making these lower makes the revs drop faster, and vice versa.

There is also a scalar value, Min mph/idle, that is the vehicle speed below which the PCM will control the idle speed. The stock value is 5, drop it to 2 to have the idle speed drop faster when coming to a stop/rolling...

nickel417

Thanks! In between seems to be a bit better but the idle still seems to be hanging slightly. I used the table you provided. Also I noticed today that startup Air/Fuel was around 17 or 18:1, is this normal? I have a short recon datalog from today if you would like to take a look at it.

cliffyk

The idle will remain up around 1000 to 1050 until the car stops moving, even with the Min mph/idle set to 0. This is to keep the revs up until the car is stopped to ensure sufficient power steering hydraulic pressure to keep the hydroboost brakes happy.

I am not sure what you mean by "...startup Air/Fuel was around 17 or 18:1..."? Do you mean literally at startup, if so then it would not be something I'd worry or even think about--what is the AFR after it's been running 20 to 30 seconds?

nickel417

after about 20 -30 seconds of idle the A/F is around 15.8ish