Onyxyth

iTrader: (2)

MSPNP2, 1.4.1 firmware. The issue I have is when starting the car it will zoom to ~2700 rpm for a few seconds and then slowly come down to ~1400 over the course of another 5 seconds or so. By then it's in closed loop and evens out. But what causes the initial high idle? I can't imagine revving to 2700 while the car has barely any oil pressure is doing it any good. I thought this was potentially the cranking idle duty, but that didn't make a difference.

I don't have logs at the moment but I can get some tomorrow. Just looking for a few spots to check first.

drizzay222

You probably need to switch back to open loop and tune idle warmup duty until it behaves as you would like then switch back to running closed loop.

ridethecliche

iTrader: (2)

P0@$T t00n.

Onyxyth

iTrader: (2)

I don't think there's any reason to switch back to open loop for this issue. Everything else works fine.

Ya I should have. I'll post it tomorrow ASAP when I get to my tuning laptop (which is in the car ATM).

DNMakinson

iTrader: (3)

Im a bit confused by your combination is a MSPNP, which I understand is a MS2 variant, and 1.4.1 FW.

Nonetheless, for MS3, there is this:



Similarly, for MS2, there is this:

Onyxyth

iTrader: (2)

Sorry it's 3.4.2 firmware. The one with the sliders for idle control.

Anyway that's the exact option I was tinkering with but it did not seem to make a difference. Maybe I'll try larger/smaller values.

DNMakinson

iTrader: (3)

The only other variable, assuming your CL idle values, such as targets and dashpot are correct, is the Crank-to- Run Taper that controls how many seconds the Crank Duty Steps are held.

curly

iTrader: (25)

Hopes and dreams. Certainly not software calculations.

Switch to open loop, never look back, and enjoy life.

Braineack

iTrader: (62)

idle cranking duty/steps table. same as with warmup.

what you need to tune now is the idle initial values table (and activate it) as well as the RPM targets tables, so you can give the PID code a rough place to start

Onyxyth

iTrader: (2)

There is no hope. I'm switching to open loop.

Kidding - it was Idle Cranking Duty as DNMakinson pointed out. I just wasn't using small enough values when I tried last time. I have it set to rev to about ~1500 on cold start, with a 4 second crank-to-run taper. Everything works great now. poscats all around.

ridethecliche

iTrader: (2)

It really helps to go through all the values on your range using the idle valve test mode and noting the important rpm: idle valve relationships that are important to the initial startup values you want.