I have a misfire only when the AC is on and the car is at idle. There is a slight stumble on take-off but other than that she runs great. Any solutions to this problem?

thanks,

 

Check spark plugs then wires and/or coil on plugs and all that is fine could be fuel injectors or a vacuum leak

 

Does it do it only when you have the a/c on at idle, or just at idle period? Could be some timing issues. You could also try adjusting the AAC valve; it's got a little rubber piece that comes off and you can adjust it with a screwdriver to help with your idle. If it starts misfiring whether you have the a/c on or not, it could very well be an injector on it's way out. The death of these injectors are intermediate; they'll keep kicking on and off until eventually they just die.

 

Yes it only misfires when the AC is on and the car is at idle i.e stop lights, sitting in traffic.
Fuel injectors are new (OEM). I will check the plugs, wires and vacuum lines

thanks

 

Forgot to ask, do you have a VG or VE? If it's a VG, after checking your plugs, wires, vacuum, ect, try adjusting the AAC valve. Just have the car idling with the a/c on and adjust the valve until the idle stabilizes.

 

Yes its a VG,

Thanks for the information, is there any particular direction I need to turn the adjusting screw?

 

Just try adjusting the screw when you have the car idling and the a/c on. Just turn either direction until the idle starts to stabilize.

 

Are you sure it's even a misfire as opposed to just increased vibration when the compressor is engaged and idle bumped with it?

 

Yes,

I am sure, it has a distinct misfire when the AC is set to on.

Thanks