shaking when ac is on

[jimmythesaint]

question,,,the wifes vz when at traffic lights shakes and shutters with the a/c on when ya turn the a/c off its ok ,,,,,
could it be the injectors,,,really confused,,,did have a sluggish problem before but thats been fixed wiyh new spark plugs,,,,
it starts coughing and shaking in drive or reverse mainly in park not so bad,,,but only when a/c is on,,,,any ideas,,cheers:bang:

 

[loopie]

iac valve, or some people call it a idle up control valve, basically it increases the car idle when the air con is on.

 

[Danoz]

The vz has an electronic throttle so it just opens up 1-2% more when the AC is on. It has no IAC valve.

You should clean the throttle body... See if that helps. They build up a bit of gunk just after the butterfly.

 

[VTCommoDude]

Mine did that years ago. It was running really rough. Mechanics couldnt figure it out. I bought 3 cans of carby cleaner and sprayed inside the engine through the air intake. All the carbon and crap comes out. Just do a little bit at a time because it is hard to start the car. If you do too much, it will be really hard to start. When it does start, a massive black cloud shoots out the exhaust.

I sprayed all the sensors and took off the IAC valve (it was completely blocked). It has run like a new car ever since.