newbie question . for sc idle rpm
 

hi guys , i just got my sc week ago . i just change oil , now when the car is cold start the idle rpm about 2000 then warm up, the idle rpm drop and stay on 1200 - 1300 is that normal ? or too high ?what is the normal rpm for sc thanx SmileWavy

800 to 850 rpm is normal when warm.

hi timmy , do u know what can i do to make the rpm drop to 800 . thanx

turn the idle speed adjust screw with a flattip screwdriver. look for the big slotted screw where the throttle is on top of the engine driver side.

thanx schumlcat . and also like to ask where is the mix adjustment i could find it , can any one show with the picture thank you so much

It is right on the top of the air mix assembly next to the fuel distributor . There is sometimes a rubber plug in there.
Ypu will have a far bigger efect on idel with mixture than idle control. If you can get your hands on a LM1 or other gas analyzer I would set your base CO adjustment , then adjust idle.

i will give try , thanx

i just try to tune the idle adjustment and mix adjustment , even worst now , the idle rpm going up and down then the car shut down . what can i do now , should i take to the shop to fix it ? is that will be very expensive ?

CIS Primer for the Porsche 911
You should read this and understand the content before adjusting anything on your CIS.
You probably only needed to turn in the idle air adjust screw a little to drop the rpms.
Try to remember what you did and do the opposite to get it running again.
High idle is better than no idle....
When adjusting air and fuel mixtures a little is a lot!
Turn idle screw in 1/4 of a turn, rev motor for a bit, release and see where idle settles down. Slowly repeat until you find it.
You really don't want to mess with the richness adjustment too much ever.
Once you know what you are looking at read this thread if you don't want to take it for tuning with an analyzer.
http://forums.pelicanparts.com/porsche-911-technical-forum/387704-how-setup-cis-no-gauges.html

You didn't happen to overfill the oil did you? If oil made it into your CIS system your idle will change.

no i dont think i overfill the oil

just randomly adjusting the air fuel mix was not a good idea. it is usually done by someone with a tester that lets you know when the mixture is right.

my car now when warm at around 900 now ,is that ok ?

Yes