Hi all,

I have a strange problem with my 2004 Civic LX (Canada) with 260000km (162000 miles).

The engine runs fine except when the AC and cooling fans are running.

If I give throttle and the fans are not running, the engine goes back to normal RPM. If I give throttle and the fans are running, the RPM hangs at 1300-1400 RPM for 4-5 seconds and then it goes back to normal, around 750-800 RPM.

I've seafoamed the carb and nothing changed.

Any idea?

Thanks

 

try cleaning the iacv you can easily do it yourself with some carb cleaner just be careful not to strip the screws. there's a DIY here http://www.civicforums.com/forums/11...e-up-mods.html

 

Thanks for the links, I've cleaned the IAC few weeks ago but it didn't help.

What I don't understand is why RPM hangs only when fans run AC on

 

yeah i don't know maybe its a voltage load issue ?? sorry but you exhausted my mechanical ability maybe someone else will chime in ???

 

I thought about a bad ground but my ground cble that goes from the front of the car to the engine block is new and I've cleaned the surface before installing it.

Also, when both fans run, it means the AC clutch is engaged which may point to something related to the AC.

I did another test tonight, I turned on rear defrost, mirrors defrost, high beam, wipers and the RPM was fine, it didn't hang like when the fans are running (ac clutch engaged). This makes me thinking of an AC problem.

 

Also, no CEL or code