Mk4 1.6 idling issue's

[Clarkee_vw]

hey everyone,
My Mk4 1.6 8v golf is playing up big time. Doesn't like starting when its cold and blow's black smoke and sounds like its running on 3 cylinders for about 30 secs. Once its warmed up it makes poping sounds out the exhaust every now and then. When i'm driving it its fine or got the aircon on. Can anyone help me please?

[Golf Loon]

Vacuum leaks. Check the plastic pipes around the intake, take the cover off and the pipe down to the oil brether in the middle of the motor.
If not, scan it and it will be the magic three. Maf, temp sensor and Lambda sensor.

[Jmac]

Could be 2 of the magic 3, lambda doesnt come into play till the system is in closed loop ( warm), have it scanned and have the live data read. My guess would be throttle body not going into fast idle on cold and the system having too much fuel ( black smoke) does your secondary air pump run?? the pipes are bad for coming adrift from them thus no secondary air on start up so black smoke
cheers
Jmac

[Clarkee_vw]

just an update,
fixed the idling problem, it was the throttle body. It was very dirty but after a clean with throttle body cleaner it runs beautifully

[Tao]

just an update,
fixed the idling problem, it was the throttle body. It was very dirty but after a clean with throttle body cleaner it runs beautifully

hi there,
can you buy the cleaner and do the wash yourself?

cheers,

[Jmac]

Yep makes sense, good work
Jmac