The stock 99 ECU appears to use a 5ms dwell below 1000rpm and taper linearly down to 3ms above 2000rpm. To do the same thing in MS I added the following lines:

if (outpc.rpm < 1000) {
utmp2 += 20;
} else if (outpc.rpm < 2000) {
utmp2 += (2000 - outpc.rpm) / 50;
}

after:

utmp2 = flash4.max_coil_dur;

in ms2_extra_main.c. I'm using the 2.1.0d code base. I was hoping to solve the rolling idle problem I've had for years now but it didn't work. It does seem to have improved my acceleration out of idle but that's difficult to say for sure since I've been re-tuning everything including accel enrichment.

Just thought I'd post this in case someone else could find it useful.

 

2.1.0d is pretty old, you tried using the newer code versions, 3.2.1?