rough idling

[leeboyd]

hi guys, i have a 3vz fe engine camry, automatic with air conditioning.

i have noticed in the last couple of weeks, that when i have the air con running and the car is idling at the lights etc, that when the fan motor cuts out, instead of the rpm returning to the regular 750 rpm, it is dipping to about 500 rpm and making the engine vibrate, this usually only lasts a few seconds and then returns to 750 rpm mark.

also i have noticed that when the fan motor kicks in again, the rpm only lifts to about 1000 instead of around 1200 to 1250 of a few weeks ago.


without aircon on, the car idles perfectly at 750 rpm all the time.


i have heard these models have some kind of air con idle up valve that is meant to adjust the idle of the car when the fan motor is clicked on and off when the air con is running.

does anyone think that a simple replacement of this valve (yet to be able to locate it) will fix the problem, or can anyone think of any other problems which may be causing this to happen???


thanks in advance.

[ToyotaToday]

Originally Posted by leeboyd

hi guys, i have a 3vz fe engine camry, automatic with air conditioning.

i have noticed in the last couple of weeks, that when i have the air con running and the car is idling at the lights etc, that when the fan motor cuts out, instead of the rpm returning to the regular 750 rpm, it is dipping to about 500 rpm and making the engine vibrate, this usually only lasts a few seconds and then returns to 750 rpm mark.

also i have noticed that when the fan motor kicks in again, the rpm only lifts to about 1000 instead of around 1200 to 1250 of a few weeks ago.


without aircon on, the car idles perfectly at 750 rpm all the time.


i have heard these models have some kind of air con idle up valve that is meant to adjust the idle of the car when the fan motor is clicked on and off when the air con is running.

does anyone think that a simple replacement of this valve (yet to be able to locate it) will fix the problem, or can anyone think of any other problems which may be causing this to happen???


thanks in advance.

It sounds like a electrical problem, in particular, its your alternator, regulator, alternator brushes, or alternator belt is loose. I would start there. The air con drains a lot of current, so if there is a electrical problem, your idle will be rough.