Hi,
I am a new owner of 1983 911 SC 3.0. I just bought this car last month from other States and I have to get it smog and pass the California vehicle inspection within 2 months.
I notices that it is missing frequency valve relay that located next the Lumbda control box but the car start with up with a strong smile of gas. After it warm up the idle did not really come down. I don't think I can get it to pass smog check so, I bought a new Bosch relay and oxygen sensor to replace it. After I've replaced the relay and oxygen sensor the car will start right up and get about 1600 rpm(cold engine) then 1200 rpm( warm engine) I can not really adjust idle down because when I turn it down the idle stay the same . However, if I remove the frequency valve relay the rpm will not change but when I plug it back the idle will drop down to 300 rpm-400 rpm then dies. I used propane to check for vacuum leaks and found nothing. I also check auxiliary air regulator and it seem to be work find with 27.5 ohms. If I keep the engine running with frequency valve relay plug the engine will run very nicely but after it warmed about 2-3 minutes it will suddenly dies. I can get it start again but a little difficult and the idle will be very low about 400 rpm -500 rpm then dies.
I could not find any answer that match my problem because most of the problem is cold start issue. Can anyone give me some suggestion?
Thank,
Ken