A/C Idle

[Ajbent86]

Recently my idle increase for my A/C has quit functioning. Originally I thought it was simply an adjustment to the idle screw but i was wrong.

When the A/C is turned on, it no longer "advances" the idle when it’s turned on. The end result is my idle is at about 400 when sitting at a red light with the A/C compressor on.........

Hopefully this is an easy fix that you guys already know about. I hate sitting at a red light thinking to my self: "Please dont stall....."


It is an 89 DX 4-door 5-speed Carb.

[russiankid]

Most likely the A/C idle boost diaphragm.

[Ajbent86]

Is that a serviceable part? Or does it have to be replaced?

[russiankid]

I don't think anyone sells a repair kit for it. You can replace the part with a good working junkyard unit or a brand new one from the dealer. Just get a vacuum pump and test it. If it doesn't hold vacuum then thats your problem. If it does, then it could be the solenoid that directs vacuum to it.

[Toneloc5145]

Originally I thought it was simply an adjustment to the idle screw but i was wrong.


When you say this, are you talking about the regular idle screw, or the A/C idle screw. I know, for some reason, that my A/C idle screw backed out over time and my idle never increased when i turned the A/C on. I was just playing around one day and turned the screw back in, and now my idle "boosts" like its supposed to.

[Ajbent86]

When you say this, are you talking about the regular idle screw, or the A/C idle screw. I know, for some reason, that my A/C idle screw backed out over time and my idle never increased when i turned the A/C on. I was just playing around one day and turned the screw back in, and now my idle "boosts" like its supposed to.

I was refering to the A/C idle screw.

I went down and looked at it again this morning, the linkage that connects the "idle boost" to the throttle does not move at all when the A/C button is pressed. So at least now i know where the problem orgin is......