Getting M1 Drive by Wire to Return to Idle

[kurt_delbene]

I have an M1 controlling my '67 Mini Cooper S, including using a Jenvey throttle actuator for drive by wire. Sometimes when the throttle is released from roughly 3k RPM, it doesn't settle back to it's idle speed of 800 RPM but instead sits at around 1600. If you blip the throttle, it returns to idle. I've read the documentation a ton of times and tried every parameter involved in the return to idle process in an effort to rid the problem. Do you have suggestions on what parameters to focus on for this particular issue? If i just wanted it to drop immediately to idle when I release the throttle, what would I set to do that? As I said, the behavior is irregular, with the engine returning to idle most of the time.

Thanks!
Kurt

[David Ferguson]

A good log will answer a lot of questions. I think you need level 2 logging with either DBW or Paddle Shift as there are a lot of channels that sometimes need to be monitored, and most of these aren't transmitted on the CAN bus so you could log them with your dash.

You probably need to increase the value of Idle Am Ramp Down Limit.
Then make sure that the Idle Mass Flow Feed Forward Main has good values for the Engine Speed of "Idle Aim Main + Idle Aim Compensations + Idle Aim Ramp Down". This engine speed needs to be above 1600 for the Idle Aim Ramp down to help retard the ignition to get the engine into idle.

So to start -- when the Engine Speed is hanging at 1600 RPM, what are the values of these channels:
Idle State
Idle Aim
Idle Aim Ramp Down
Idle Activate Throttle Pedal
Idle Mass Flow
Idle Mass Flow Feed Forward
Throttle Aim State
Throttle Aim
Throttle Pedal
Ignition Timing
Ignition Timing Limit Advance

[Stephen Dean]

Hi,

In the Idle Mass Flow Feed Forward Main table add a column 200 rpm up on the highest column that you already have, and use values in there that will drive the throttle closed.