Timing and Mixture Adjustment Help

[andster]

First, I am new to this forum and I have to say this is a wonderful resource. With the help I have seen here and a few references, I think I can tackle about anything.

I bought my first 911 (83SC) a few months ago and am just getting up to speed on its condition mechanically. Its beautiful at first glance, but has been neglected so its definitely my project car. That is for another month or so until my wife has twins, then the cover goes over it for some time. For the record, I bought it before we knew we were having twins.

The car came from Virginia and I live in the Denver area (about el. 5000ft). I need to adjust the mixture as it failed emissions and Im sure the timing needs adjustment as well. I read a couple of threads on adjusting the mixture and Bob Tindel's seemed straight forward. He recommends using a high-impedance digital meter and I have an old Sears product needle type gage. I wondered if this will work or if there are any other thoughts about getting the proper adjustment.

I also wondered where I could readily find the specs for setting the timing (both idle and 6,000 rpm) and if a vacuum hose needs to be disconnected. I bought the 101 Projects manual but I wasn't sure if I should set timing to 5 btdc or another setting to compensate for higher elevations. Any help would be appreciated.

Andy

[Gunter]

Lots of help here if you do a search on mix adjust.
Also, get a Bentley SC Repair Manual.
You'll need a long, LONG 3mm Allen key and a Gasmeter in the exhaust.
Your '83 may have the access hole for the 3mm Allen adjustment-screw still plugged with lead.
Sounds like it'll be stored, so, put 2 bottles of injection cleaner and a bottle of Stabil in a full tank, run it through the engine for 10 Minutes.
More info on storage here.

[andster]

Thanks Gunter. Ill do more searching. I tried simply adjusting the mixture and idle speed and can't seem to get the CO low enough. Im now having problems with low oil pressure as well.

[len911]

Check here: CIS Idle Speed and Mixture Setting Without an Analyzer
Ballpark adjustment of CIS idle mix

Lou

[andster]

Thanks Lou. Ive read up on Souk's recommendations for the field test and have backed off the mix adjustment to lean it out so I can pass the CO emissions test. The field method however is not allowing me to get the CO to pass. I ran the car through the emissions station 3 times; the first time CO was at 135, then 33 and then back up to 47 (passing is 30). Each time I leaned it out. The car has been running well, smooth idle, but I think its time to check it with a CO monitor. Are these readily available and reasonably priced or should I take it to a shop?

[RoninLB]

install new spark plugs.

Summit used to, maybe still does, sell some joy juice to mix with fuel to pass emissions.