S54 high idle

[anaphe]

Hi guys,

Just a quick question / quirk about my s54 swap in my race car. The idle is a bit on the high side, it idles at 1200 rpm.

Stock engine and ecu.

I am pulling the RPM from the ECU canbus (Using an AIM dash and the Z3M protocol). I have also verified the RPM using a timing light on one of the coil packs.

Any ideas on how to set the idle lower?

A

[nando]

have you read any codes out of the DME? there would certainly be some sort of error code to tell you where to look.

a cheap $25 PA soft 1.4 scanner would read them out for you, or you could find INPA.

[E30Strube]

The idle is adjustable and can change it to 800,900, 1200 etc. It could simply be a setting change using a BMW scanner.

[nando]

huh?

the idle has a PID loop with a target curve - it's not adjustable unless you reprogram it, you can't do that with a scanner tool.

[E30Strube]

huh?

the idle has a PID loop with a target curve - it's not adjustable unless you reprogram it, you can't do that with a scanner tool.

I vaguely remember settings for idle adjustment (made to the throttle actuator) within Autologic, not the typical code scanning tool. It's been a awhile, so my memory may be failing me and I could be wrong.

[nando]

That is a test option. You can't adjust the idle without flashing the DME - which at the very least, requires hex editing and checksum corrections, not to mention different map offsets for the 30 or so different HW/SW versions..