Hello All,

Im new to board, thx in advance for your help. I just got a newly rebuilt Hitatchi carb(Ca Model) put on 85 Niss 2.4z motor. Engine idles real smooth and runs good. The problem is when I turn on the ac the dash pot-FI control post goes in and out causing the idle to go up and down. The vaccum hose going to the dash pot is good. Can someone pls tell me how to fix this problem?

Thank You,

Mike

Hello,
I too have a similar problem.
I have an 86 720.
Went the A/C is turned on via the push pull switch on the blower control, the engine surges until put into gear (Automatic).
After put into D or R the engine idles quite normally until placed back in park or neutral.
Can anyone offer an Idea of how the A/C idle step up system works and how to diagnose/repair this particular symptom?
Thanks, Ibjman

Hello,
I too have a similar problem.
I have an 86 720.
Went the A/C is turned on via the push pull switch on the blower control, the engine surges until put into gear (Automatic).
After put into D or R the engine idles quite normally until placed back in park or neutral.
Can anyone offer an Idea of how the A/C idle step up system works and how to diagnose/repair this particular symptom?
Thanks, Ibjman

I found that lowering the "fast" idle speed created by the A/C step up solenoid (adjust the screw in the top of the solenoid, counter-clockwise) pretty much cured the issue. The solenoid was set way to high. I backed the screw out a couple turns lowering the A/C idle speed and the idle stopped racing up & down. Seems mine simply was set Too fast.