Re: STILL running a little rich...??

["dmcmike2002" <billsfanmd@xxxx>]

andy,
i am cutting and pasting from an old message on the DML. It is also 
in the Technical manual with a picture but not a real detailed 
explanation. if you are standing behind the car use your left hand 
and reach the front of the engine about half way down. the 
diagnostice plug is about an inch and a half wide and has a black 
plastic cover. It is seated in a black metal bracket. you can unclip 
it from there and lift it up to use it. you will see the male plugs.

here is a a cut and paste on setting your mixture:
If you have a dwell meter ($35.00) you can get the air fuel (AF) 
ratio
pretty close.
1. Find the diagnostic plug. On the left rear fire wall. Attach the 
ground
from the dwell meter to pin # 2 on the plug. Attach the other wire 
from the dwell meter to pin # 3 on the diagnostic plug. Set the meter 
on Dwell. 

2. Crank the engine. Let it get warm. This is so that the oxygen 
sensor is sending a good signal to the Lambda Control unit. (When the 
engine is cold the computer sends a fixed signal to the frequency
valve). You can see this "fixed" signal on the dwell meter. The read 
out on the dwell meter will be 60% duty cycle or about 54 on the four 
cylinder scale. When the engine gets hot the computer starts looking 
at the oxygen sensor and adjusting the frequency valve to adjust the 
exhanst level. If the dwell meter needle swings high (60% to 70% or 
54 to 63 on the four cylinder scale)on the scale when the engine is 
warm the mixture is set to lean. Turn the AF screw on the distrubter 
clockwise just a little with a 3mm allen wrench. Remove the allen
wrench from the AF screw, cover hole and let the system settle and 
look at the dwell meter reading. If the needle swings low (29% to 37% 
or 26 to 33 on the four cylinder scale)the mixture is set too rich , 
turn the screw counterclockwise
to lean the mixture.

again, go easy as an 1/8th or 1/4 turn does alot. Your ears will also 
tell you if you are getting closer to a smooth idle.

hope this helps
Mike C
2109
> 
> since i don't have access to an exhaust analyzer for CIS, can you 
explain 
> exactly how to infer the CO ratio from the dwell reading? > Andy