Re: [DML] improper lambda readings Date: Tue, 14 Oct 2003 12:51:34 -0400

["Tom" <tomcio@xxxx>]

Hi Andy

What you are describing actually sounds right! The problem is that you
cannot look at the numbers on the meter. If it reads 30 with the O2 sensor
disconnected it means that it is actually 50%. Just foget what the numbers
are on the dwell meter scale. Look at it this way - the meter goes to 60
and
that is 100%. Then 30 will be your 50%. 15 will be 25% and so on.
Disconnect the O2 sensor and make sure you get a reading of 30. Then
reconnect the sensor (make sure the engine is warm and spark plugs are
clean - rev it up for few seconds) and the needle on the dwell meter should
move from just under 30 to just above 30. When it does, it's perfect.
Remeber, it's not the dwell that you are measuring. It a percentage of the
scale on the meter.

Good luck!
Tom Niemczewski
vin 6149 (5-speed, yeah!)



> 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