Low idle when AC's ON, supposedly a servo issue

**mark1985** · December 23rd, 2013 07:22 PM

Hi guys!

My car is a 95 Galant VR4 (not the AWD version)

I'm having this issue with my idling. They say 600 up dapat sya when idle and it's like that naman until I turn on my AC. Naglalaro nalang sya around 300-500 range whenever i do so.

Been reading the forums and doing a little bit of research and it seems nasa servo daw ang diperensya pag ganun. I read somewhere here na servo bypass daw then lagay ng idel-up ang practical solution since a brand new servo alone costs alot.

Anyway, i don't really know what the servo does except that it's supposed to pull your rpm up when you turn the AC on (tama po ba?). Been searching google for servo pero all i get are robotic servos, i'm not really sure what this servo really is since I'm just new pagdating sa pagkalikot ng auto haha What's the first troubleshooting procedure na ginagawa nyo to isolate the problem? Hindi naman ako namamatayan and the car's running really well but I'm afraid na baka lumalala yung problema if i don't deal with it now.

Hope to hear from you guys. Been learning so much on this forum. Merry xmas all!

**JohnM** · December 23rd, 2013 07:27 PM

The servo is also know as the Idle Air Control Valve (IACV). It increases the air that enters the engine to compensate for additional load like AC and power steering.

Bypass using idle up is a good workaround. It only compensates for the AC though. Your steering might get heavier and your lights at night might get dimmer because the engine can't compensate for the additional load.

**mark1985** · December 24th, 2013 07:17 PM

Just the info i needed! Thanks johnm!

I see. I thought bypassing the IACV will give the engine more room to breathe.

Iniisip ko if i have my servo cleaned up instead first. But i've been also hearing na medyo hit or miss din ang cleaning.

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**vinj** · December 24th, 2013 11:31 PM

There's a fix to the servo issue before but i cannot recall exactly what. With the case of our 94 Galant VR, we just replaced the servo with a new, OEM one and it served us well way until we sold the car last year (after 18 years with us).