AW: [DML] Re: Can someone explain this? (distributor positioning)

["Elvis Nocita" <elvisnocita@xxxxxx>]

Here are some old description that I have from the DML.
Checking and reading old mails can be very helpfull along with
google...O2 sensors are very common and the all work the same way...



Using a dwell meter to adjust your fuel idle mixture.

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----

Attach the dwell meter to the diagnostic plug near the firewall on the
engine left side.
The dwell meter connection is the upper right corner pin on the diagnostic
plug. Start
the car. The dwell meter should read steady with a cold engine. After a
couple of minutes
 the engine should warm and the Oxygen Sensor will begin sending a current
to the ECU
computer. When the ECU sees this output from the Oxygen Sensor it will begin
sending
signals to the Frequency Valve to regulate the fuel mixture. The dwell meter
should now
begin to pulsate in a range of 15-20 degrees. Set the dwell meter to the
four-cylinder
range and adjust the CO idle mixture screw to an average reading of 45
degrees. What you
are actually reading is the duty cycle of the Frequency Valve. The fact that
the dwell
meter begins pulsating means the ECU is working. If the ECU fails to work
check the ground
 connections. Run a separate ground wire from the engine block to the ECU
mounting bracket
 ground screw. Redo the ECU test. Reference the Fuel, Emission and Exhaust
System section
in the repair manual section D:04:14.


Checking the operation of the oxygen sensor.:

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Place a jack under the rear frame and raise the rear of the vehicle enough
so you can
reach into the left-hand wheel well and get at the connector for the oxygen
sensor.
Pull back the rubber boot covering the connector and expose the connection.
(Do Not unplug
 the sensor at this time) Set your voltmeter on a millivolt scale and attach
the positive
lead to the sensor. Attach your negative probe to a suitable ground. Start
the car and
observe the voltmeter. The voltmeter should rise to between 400 and 600
milliamps as the
engine warms up.



-> of course the author meant 400 to 600 millivolts, not milliamps.
the sensor needs to be hot to work correctly. Also it won't change very much
if the mixture is already set way too rich or too lean.

Also - being pretty sure that something isn't defective doesn't help at all.
You need to know that is ok !
How old is the lambda sensor ? can you get it out ?
I think it is something like 20 bucks for a new one....problem might be
getting
the old one out.

Elvis




I just got my current ECU from DMCH just a few months ago, I'm
pretty sure it isn't defective?is there any way to test the
frequency valve part of it? How do I test the O2 sensor? When I
changed the plate that mounts all the connections and coil on the
engine bay bulkhead, I noticed wires cut and spliced into different
wires [behind the plate inside the pontoon]; I noticed in particular
one of the wires had a capacitor spliced in, was this a recall or
update, or someone else's mess? It wasn't any of the wires from the
FV plug though?-----Dani B. #5003






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