Rich stop on '86 4 ksq

[rizov_d at shaw.ca]

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CO adjustment screw has effect on engine work but not on the readings (mA).



I was able to kill the engine with lean and rich adjustments. Readings were
not changed.



What is “CSV”?



Besides the visual inspection for vacuum leaks (cracks) is there any more
advanced method?



(I have this car for 5 years)



Dobby



-----Original Message-----
From: rizov_d at shaw.ca [mailto:rizov_d at shaw.ca]
Sent: Thursday, January 02, 2003 4:47 PM
To: Tony Lum
Subject: Re: RE: Rich stop on '86 4 ksq

I don’t have a spare ECU or altitude compensator.

Is there any way to test the compensator?



There is something else I have observed:



With engine running and differential pressure current steady at 17,7 mA:



If I close the full throttle switch the current changes to 10,7 mA



Immediately after releasing the switch (open) the current is 7,7 – 8,4 mA but
only for a blink of an eye and changes to steady 17,7mA.



I even tested the ECU side of the connector, mainly for ground or broken OXS
wire, but tests went o.k.



The only thing I can think (beside altitude compensator you suggested) is the
flow meter potentiometer.



Thx,



Dobby

I'll have to look that one up in the Bentley. Basically it is a pot similar to
the mass airflow sensor.  The "arm" is attached to a pressure chamber which
changes the resistance based on air pressure on the chamber.  However, the
change effect is pretty miniscule, while your readings are almost off the
scale.  Normal current at idle should be 8-10 mA, so you're running extremely
rich.  Does the CO adjust screw have any effect at all?  (turn to the left to
lean, turn to the right to rich).  Also are you positive all vacuum
connections are air tight?  2 sneaky leaks come via the oil filler gasket
which when old gets old and cracked.  The second is the plumbling around the
CSV.  There is a connection there that is hard to see.  I accidentally bumped
it off and my '85 4kq started to run very rough.  If this happened suddenly,
then re-check all hoses including the big one to the M-A-S for cracks.  If
this a new to you car , then someone has "run up" the adjustment to compensate
for the extra air and the system is completely out of adjustment.

Tony