S13 KA24DE A/C drags motor down hard when in neutral

[zagoo6]

Hi new to forums here, i searched and searched and i cant find anyone with this problem

When the A/C is on and put the car in neutral while moving, the rpms drop down to about 500 until I stop, then it bumps back up to normal idle. I can't figure out whats wrong with it and its driving me nuts!
I drive a 89' Coupe s13 with a 93 ka24de motor
If anyone can help that would be much appreciated!!

[zagoo6]

bump please i need to figure this out and im stumped

[Harrythook]

A bit of research here on the forum and you can find the answer. Sounds like either the ECU is not seeing the AC is on (will not compensate for load) or your adjustments are off.
Start with making sure timing and idle speeds are set correctly.
1991-1994-240sx-setting-adjusting-idle- ... 54123.html
If that is a correct then look at the factory service manual (available on this site) to fault trace the AC input to ECU.
Good luck, should be an easy fix.