Wierd idle problem
 

Not a super urgent issue, but I noticed some strange idle issues on my 73S. say the car is cold, she needs hand throttle to run okay, normal. once the car starts to warm up a bit it idles just fine at around 1000 rpm, I think that's where it was set the last time the MFI was tuned up (about 4 months ago), again normal. once the car gets up to operating temperature, the idle moves up to around 1500-1600 rpm, a bit high. Any ideas on what the cause is, or any ideas on where to look?

Thanks,

Brad

Brad,

It sounds like your idle speed is adjusted too high ... it is supposed to be 900 rpm at an oil temp of 180 degrees F, minimum. Any other needed adjustments while warming up with the hand throttle ... a couple of times, that would be normal, but your ending idle speed isn't! It may have been an oversight four months ago, or incompetence ... but, I would strongly suggest doing some serious study at Pelican's MFI fuel injection tips page:
http://www.pelicanparts.com/techarticles/911_MFI/TipMFI.htm

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Warren Hall
1973 911S Targa

Thanks Warren, I'll check out that link, but let me ask a question - if the idle was mistakenly set at around 1500-1600 rpm, is it normal for it to start rought at around 500-600 rpm (cold), then *stabilize* for maybe 5 minutes or so at 1000 rpm (warm), then go to set idle speed at around 1500 (operating temp)? Just thought it was wierd that it went to what the idle should be set at (roughly) and sat there for a bit, and then decided to go up another 500 rpms later.

Thanks again,

Brad