Idle to high !

[Zithlord]

Hi

When the engine is warm, about 80 degrees celcius, the engine idle is about 1200 rpm. Is there an easy way to adjust this, without having to adjust other parts of the MFI or ignition?

1973 911S

John

[Chris Tallon]

I'd leave it alone. If it runs well, don't mess with it. The MFI is tricky and should be avoided unless there is a problem, and 1200 at idle does not seem like a problem to me. Sometimes you can adjust the timing a little, and that will make the difference.

Good Luck

[spydr32000]

Check your ignition timing, to be sure it is returning to its base setting. I it isn't then make sure the vacuum hoses at the distributor have a good vacuum supply to them. These are actually for retarding the timing rather than advancing it, to help the engine return to idle, it is very common for these to get blocked. Try this for a start.

[911pcars]

I had this happen recently on some parade laps around CA Speedway a few weeks ago with fellow Registry/RGruppers.

The idle wandered from normal idle speed to 3000+ rpm w/o any throttle input. The problem was a worn bushing set at the throttle linkage at the driver side intake manifold. The plastic/nylon bushings had deteriorated to a point where the crumbling remains prevented the linkage from moving freely. I noticed this earlier when the rpm fluctuation was less (and the bushings were not yet fully lunched).

This can also happen at any of the throttle bushing positions between the gas pedal and the engine.

Hope this helps,
Sherwood

[72targa]

Note this thread as well...

http://www.early911sregistry.org/for...highlight=idle