Hello guys. I'm wondering if anyone can tell mewhats up with my idle... I start it up from cold and its fine, slightly higher revs etc. But leave it 2 mins and its wandering all over the place from 1000rpm to 0. It never cuts out but putters around alot. It seems to get alot better as soon as my oil is up to temperature. Basically she's running like a pig.
It all started when i had my tappets adjusted at a local garage, but he fiddled around with the air mixture and it was fine.... untill i drove off and pulled up to the first junction!
I have tried adjusting the air mixture myself but think i am just making it worse...
Does anyone know whats up? What i need etc?

P.S. Its a 94 SiR

 

Do not trust the dash mounted tach. Think about it, if the rpm really went to zero it would be stalled out.

First make sure your throttle cable is not too tight or binding. If the check engine light is on, pull the code and find out why.

Fully warm up the engine, turn the air conditioner off, and unplug the IAC valve on the back of the throttle body and the idle speed should decrease. If it's going to stall, pull the throttle open manually as needed to keep it running. Adjust the air screw on the top of the throttle body so the engine barely keeps running (400 rpm). Do not adjust the throttle plate stop screw on the front of the throttle body. If someone has adjusted that, you want to reset it so the lever hits the screw just before the throttle plate closes fully so it does not slam shut. After adjusting, reconnect the IAC valve and you should have a normal idle. If it's still unsteady the IAC valve may be dirty. Unbolt it and clean with carb/throttle body cleaner. Then of course there's the possibility something else is wrong. But usually that will cause poor performance on the road not just idling.

You're adjusting the minimum air flow only. The fuel mixture is always driven by the computer.

 

^^^^^ what he said on the money