Rough Idle When A/C is on

A forum for lovers of Infiniti's hot-rod crossover, the FX! In 2014, all FX models will be named Infiniti QX70, in line with Infiniti's new naming structure.
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Joined: Wed Jul 13, 2016 1:58 pm
Car: 04 Infiniti fx45

Rough Idle When A/C is on

Postby DatsunToInfiniti » Tue Aug 09, 2016 12:31 pm

What's up guys. I have a 2004 Infiniti fx 45 with 214,000 miles. Vehicle runs great except it idles rough when I have the a/c running and I'm idling (sitting at red light, drive thru, etc.) I've recently done some routine maintenance: wheel bearings, spark plugs and coils, lower control arms, tire rods etc but I'm not sure what's causing it to idle rough when the a/c is on. I've been told is may be the IAC or the TB needs to be cleaned but I've reads forums that state not to touch those. Any ideas? Thanks.

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Re: Rough Idle When A/C is on

Postby lexcrob » Fri Aug 12, 2016 1:44 am

Disconnect the negative battery terminal and carefully scrub out the throttle body with a toothbrush and brake cleaner or similar. Give it some time to evaporate after then reconnect negative terminal and crank her up. If it still idles rough and it never did before" it is common for most vehicles to idle a bit rougher with the ac on.* At that point search to see if there is a idle relearn or reset for your vehicle. If not call the dealer to spot check for an ecm update. If all that fails. Sell it or live with it until your ecm throws a light telling you it is a problem and an idea of what is causing it.

Good luck,

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