how do you adjust idling?

[M]

i have a car with a carb engine currently idling at a low 400 rpm and 900 rpm with the A/C on. i think this is too low as i sometimes stall during cold starts. how do i adjust this? i know it's just a screw, but which one? thanks.

am planning to let the engine idle at around 800, which should just be enough, right?

[wildthing]

What car?

Have you considered na baka marumi lang ang carb mo....buy a carb cleaner spray and spray the carb clean first (don't remove the carb just the carb filter and cover and casing so you could see the carburator). Spraying it while the car is running is sometimes better.

If this doesn't do the trick then try the next:

Normally the idling can be set by 2 screws....one screw actually pushes the rotating mechanism that is linked to your gas pedal....try tracing the route of the gas pedal cable and observe the mechanism (you might need to remove the carb filter casing/cover to see it properly). The screw is always conveniently located even if the carb cover/case is in position, however an unaided beginner will not SEE it as very obvious. If you turn the screw it will do some increase (or decrease) in the revolution of the engine (because you're actually putting up some gas). Obviously, increase is what you want.

Usually, that would do the trick na.

To further control the idling...you can also turn the screw on the "Air" or "Vaccum". It is normally the screw with the visible spring on it and found normally protruding in the (middle part)body of the carb. It is usually located at a very convinient location (just like the idling screw) even if the carb filter cover/case is intact. All the other screws like things there (na copper) are not to be touch...and they don't have a visible spring wound in the screw itself and they are not readily accessible unless you remove the carb filter cover/case.

The function of this screw is to control the richness or leaness of fuel-air mixture....it has an effect on idling but it is very difficult to access the accuracy without an O2 meter (oxygen meter/sensor). For a non-pro, I don't dare you to touch this. This is a bit advance.

The other things you should note is always take note the number of turns that you would be doing and at what direction did you turn it. This would help you put it back in the previous conditions in case there is trouble.

The last thing that you shouldn't do is to dismantle the carb....carb idling problem doesn't need dismantling unless MAJOR ang problem nuon.

hope this help.

[M]

thanks wildthing.
anyway, i already brought it to our mechanic friend and i think what he adjusted was the vacuum screw. it's fine now. thanks for the help.