I'm currently having an issue with my rpms not increasing whenever I turn my A/C on. What typically happens is as soon as I turn it on the rpms stay the same for just a second or so then I hear a ticking sound which is assume is the compressor kicking in and as soon as that happens idle will drop down to about 500rpm and slowly work its way back up to the typical A/C idle rpms (750-800ish?). It's a 2007 Nissan 350z Enthusiast Model with 74k on it. I know this behavior shouldn't happen since a friend of mine has an 04 Z and his idle increases immediately whenever he turns on his A/C. Hopefully I'll be able to figure this out as I haven't really found any posts with this specific issue. Any suggestions on what I should do will be much appreciated!

 

Doing an idle air relearn is my first suggestion.

 

Well I tried doing the idle air relearn. Still nothing. I called Z1 Motorsports and explained what was going on. They told me to try cleaning my throttle bodies. I'll report back if I get anywhere. Does anyone else have any other suggestions?

 

Clean your MAF sensors

 

My suggestion is read up on all the horror stories other people have experienced when they cleaned their throttle bodies. What's a simple thing on most cars can be a multi-thousand dollar money pit on ours.

Don't clean the throttle bodies unless you're completely read-up on the FSM procedure and follow it to a 'T'.

FWIW: It sounds more like your A/C compressor is putting a load on the engine. Could be a bad A/C compressor clutch. Check your serpentine for abnormal wear or glazing. Have someone toggle the AC button in the car and observe what happens to the compressor under the hood when it engages and listen to hear if clicks on and spins freely or if it's not engaging or stuttering.

And yes, with 74K on the clock, a MAF cleaning couldn't hurt. Just use the right chemicals for the job.

 

I did read up on some of the horror stories about the throttle bodies. I know one person who posted on here about it might have screwed theirs up because they didn't disconnect the battery? I mean as long as I disconnect the battery I should be fine right? I probably won't even disconnect them. And I know the pedal dance has always worked in my car before since I could see changes it has made in the past.

 

I was fine after disconnecting the battery, discharging and waiting on the on any caps in the system and then disconnecting the throttle bodies. Not following the steps in that order can result in dead throttle bodies or even ECUs. I did move the throttles plates very gently and slowly and was fine afterwards. It took many tries to get the relearn to take but haven't had a problem with it since.

 

Reference the FSM for your model year. Here's the [LINK] to the factory Z service manuals.