Technical AC makes car idle irregular

[damir78]

My Bravo 1.4 idles irregularly with AC on. The car doesn't cut off and I wouldn't consider this to be a problem, but this irregular idling causes AC clutch to frequently engage / disengage. Because of this, AC is not cooling the car when car is idling on traffic lights and I worry that frequent AC clutch engage / disengage could damage the AC clutch.

Went to Fiat garage, they say AC is fine and have no idea on what is going on.
Wen to an AC expert, he told me AC is fine and irregular idle causes the AC to engage / disengage.

The car starts normally, drives normally and AC operates fine while driving.
If I put my foot down in idle to keep rpms over 800, 900 rpms the AC works fine.

Does anyone know what might be the issue here?

 

[aschiuta]

Clean up the throttle valve and MAP sensor.

 

[damir78]

The engine has integrated air intake pressure / temperature sensor type
Bosch 0 261 230 030. The sensor readings are fine and test procedure for this sensor indicates sensor is OK.
Sensor readings for both pressure and temperature read via OBD software are also fine in all conditions (engine not running / idling / high rpm).

The engine has a motorized throttle body, so I am reluctant to clean it using chemicals. Anyone has some experience with this or knows the recommended / proper way to clean motorized throttle body valve?

 

[aschiuta]

This is from Stilo but same motorized throtthle body valve:

http://forum.clubfiat.ro/index.php/...eta-de-reglare-a-debitului-de-aer/#entry34340

Not need to chemicals only cloth piece.
You need to have the openings clean like in photo #8

 

[Peter Pick-Up]

A car A/C compressor is designed to engage and disangage all the time, it won't hurt the clutch at all.

www.autoacforum.com

 

[damir78]

Will try that next month when I need to service the car and replace air filter. I will remove the whole air filter box assembly, which I think will expose the throttle body valve...

 

[damir78]

Hi!

Finally got around cleaning throttle body valve. Must say I was sceptical at first. The car has less than 50k miles, and throttle body flap thingy only seemed to have minor carb build up around the edges of the flap thingy. However, I sprayed it several times using carb cleaner and wiped it with a cloth clean.

The car idle is now totally fine and AC operates normaly when car idling.

Thanks a lot aschiuta for the top tip. This came out to be a much cheaper fix then I tought it would be.

for aschiuta!