Hi ,

I have a 1982 911 SC with a small issue which sometimes bothers me so I would like to fix it if it doesn't involve buying some instruments or dismantling half of the injection system
- Engine cold : starts at the first crank , idles at 1800 rpm , after about 5 min. settles down at about 900-950 rpm. Therefore I reckon AAR and WUR are ok.
- Driving the car around , hot engine , no issues , idle 900-950. No backfire , no hasitation , runs good . Therefore fuel pump , fuel distributor , fuel pressure and ignition distributor are good.
- When I turn the engine off and starts it again after couple of minutes , it starts immediately , idle is still ok , 900-950.
- When I start the engine after 15 minutes , it starts great but idles a bit lower at 750 rpm.
- When I turn on the engine after 45 - 60 minutes , starts ok but idles at 650 rpm. I hear the engine doesn't like it but it runs . The fuel accumalator is ok , it starts straight away.
- If I leave the engine running, when hot again , idle is ok then.
- The next day cold engine starts again idling at 1800rpm.....

My question is what controls the idle rpm in these medium engine temperatures when it is not hot but it is warm enough ?
I know AAR is open only with cold engine .
Could it be something with OXS , lambda , FV etc ?
Thanks for your help , regards from Croatia

 

Seems like a minor annoyance unless of course you happen to be a little OCD like most of us 911 types. If it were me, I would try living with it until it drove me completely nuts and ready to jump off the bridge.

Cheers,
Joe
87 Carrera

 

You could check out Jims site.
http://www.jimsbasementworkshop.com/...ubleshoot.html