improper lambda readings
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improper lambda readings



List,

I am getting closer to figuring out my idle problem but i still have a little 
ways to go.

it appears that my idle microswitch is somewhat flakey- when i have 
everything wired up with the switch depressed, i can tap it with a screwdriver and the 
advance solenoid clicks each time. it clicks too fast for my digital meter to 
register which is why it escaped me until now (when my system is now wired 
properly). i have a new switch on the way but at the time it seems to be working 
ok (verified with a timing light when the car is running).

ok on to the next problem. 

first i need to know how to verify that my idle motor and lambda system are 
working properly. when cold, the car cycles up and down for about 2 minutes or 
so (getting a little chilly around here) which is normal (fixed pulse ratio 
runs rich). then it runs a little rough until it gets actually fairly smooth 
at full operating temperature. i watch with a dwell meter and i can see the 
needle change with engine running quality and temperature. additionally, the 
idle motor makes a lot of noise and the frequency valve buzzes. my last 
evidence is when i press the full throttle switch, it makes the dwell needle change 
too. does all of this add up to a functioning idle system? or is there a test 
i can do that will definitely answer the question? i just want to be sure 
this is ok before i continue.

if that is good, then on to the next problem. i am looking at the dwell 
benchmarks as listed in D:04:15 in the workshop manual. when i start my car and 
it is cold, my needle hovers around the 30 deg area instead of the 50-60. it 
is also around 30 deg give or take 5 deg when i disconnect the lambda sensor in 
the wheel well instead of 40-50 fixed needle. i can turn my CO screw until 
the needle varies from 35-45 or pretty close anyway as per the manual (O2 
sensor plugged in) but when i press the full throttle switch, it drops down to 30 
deg again. these numbers are not close to what the book shows. i tried 
turning my screw in small increments from almost-killing-it left to 
almost-killing-it right. same readings the whole way down the scale (except the swing with O2 
sensor plugged in, which seems to stray away from 35-45 as i turn the screw 
away from what seems to be an optimum spot). even when the needle is in the 
'right' spot during that single test, the car still seems to run a little too 
rough than what i know it can do. btw, i am reading the six cyl scale and i have 
the test lead connected to the orange wire for the diagnostics plug and the 
battery wire to the bulkhead battery aux terminal.

I am in total outer space right now with this dwell meter - does anyone have 
any ideas on what the problem is? apparently, whenever the car should be in a 
fixed-ratio state, the dwell reads much lower than it should be. why? it is 
this problem that makes me wonder if i need to do some testing of the idle 
motor and freq valve, etc.

many thanks to those of you that have privately emailed me and gotten me as 
far as i have, but i still need some help! at least i am learning a LOT as i 
go!!!!

Andy


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