Fwd: UrQ smog Q's, please help!

Clint F. stungun68 at hotmail.com
Sun May 20 05:01:33 EDT 2001

I don't know much about you emission readings, but the frequency for the 
idle is way off.  It should be around 50%.  Vacuum is low. On a good motor 
at idle, readings should be a steady 15 to 18 in.  Oxygen sensors should 
swing from .2 to .8 volts in a steady manner, at 2500, about 10 times a 
second, averaging at .5 volts.  A quick check on the sensor and controls is 
to disconnect the sensor.  Hook your meter up to the sensor wire, and ground 
the terminal to the computer, simulating a rich condition, the sensor should 
run up to its limit, 1 volt as the computer adjusts fuel trim.  Next, hold 
the computer terminal in your hand, and touch battery positive.  The 
resistance through your body will protect the electronics.  This should 
drive the sensor voltage to a minimum, around .1 volts.  With an idle 
problem as well, and i'm guessing it "hunts", swings up and down, that you 
have a vacuum leak somewhere.  Squeeze your intake boots, feeling for 
cracks, and see if the idle changes.  The back and bottom of the one to the 
throttle housing is popular for cracks.  Also, and you must use caution 
here, you can spray around the injector seals, any vacuum lines, and intake 
gaskets with carb cleaner to search for a leak.  When the motor sucks the 
cleaner in through a leak, your idle will change drastically.  But please be 
careful.  Don't go crazy with the stuff, keep it away from the exhaust, and 
let it dry up some before checking another area.  The last thing you want is 
the hot manifold or an arcing spark sending your car to the junkyard and 
your house to the local dump.  Keep it away from paint too.  Just in case, 
if you decide to use the cleaner to look for a leak, get an extinguisher 
Happy Quating,

>From: RndLiteBMW at aol.com
>To: quattro at audifans.com
>Subject: Fwd: UrQ smog Q's, please help!
>Date: Sat, 19 May 2001 22:57:07 EDT
><< message3.txt >>

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