Idle problems 1979 Manual
05-01-2013, 02:40 AM
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Idle problems 1979 Manual
Hi,
I bought 1979 manual 928 porsche few months ago and now I have some idle problem. Car has no ac any more and compressor has been removed. I still have that suplementary air valve hanging on crossbar and I know that it should raise my idle when compressor is on. If i remove that valve and block those two vacuum hose attach to valve my idle speed drops at 200rpm. After 2 min it starts to hunting between 200 and 400 rpm and when I step some gas it will go up and then drops 100-200rpm and almost stalls.
When my suplementary valve didnt work first, no power at all, so I forced it open all the time. Now car runs ok idle at 800rpm, but why it wont work without that suplementary valve? I did replace my aav-valve, but no good.
I bought 1979 manual 928 porsche few months ago and now I have some idle problem. Car has no ac any more and compressor has been removed. I still have that suplementary air valve hanging on crossbar and I know that it should raise my idle when compressor is on. If i remove that valve and block those two vacuum hose attach to valve my idle speed drops at 200rpm. After 2 min it starts to hunting between 200 and 400 rpm and when I step some gas it will go up and then drops 100-200rpm and almost stalls.
When my suplementary valve didnt work first, no power at all, so I forced it open all the time. Now car runs ok idle at 800rpm, but why it wont work without that suplementary valve? I did replace my aav-valve, but no good.
05-04-2013, 10:28 AM
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Hi,
I have done that. If I take power off from SAV idle rpm drops to 200-300rpm and then I have adjusted idle screw and raise idle to 800rpm idle starts to hunting from 800-900rpm and if I press gas it will go up and then drops down to 200rpm and slowly rises to 800rpm. When SAV is connected and open idle will be stable and when I press gas it wont drop to 200rpm it will stay on 800rpm. There is little bit hunting idle when engine is cold, but when it warms It works ok with SAV valve open.
I have done that. If I take power off from SAV idle rpm drops to 200-300rpm and then I have adjusted idle screw and raise idle to 800rpm idle starts to hunting from 800-900rpm and if I press gas it will go up and then drops down to 200rpm and slowly rises to 800rpm. When SAV is connected and open idle will be stable and when I press gas it wont drop to 200rpm it will stay on 800rpm. There is little bit hunting idle when engine is cold, but when it warms It works ok with SAV valve open.