Re: Milano 2.5 Erratic Idle/Aux Air Device?

["Rich Wagner" <drsavage@domain.elided>]

Jason wrote:

>Does the Aux Air Device sound like it is doing its job?

Yes.  They often don't open all of the way when cold.  They only change the
idle speed of the engine, and have no effect on mixture.  If the device is
faulty, the engine will either idle too fast when warm, or too slow when
cold.


>Should I check anything else before I replace the O2 (again!) and rebuild
>the injectors?

Yes, check the output of the O2 sensor.  With the engine and exhaust hot,
disconnect the sensor, connect the positive side of a VOM to the signal
lead, and the negative to ground.  You should see something around 0.5
volts.  You should read the same voltage whether grounding to the engine or
body.  Make sure that is the case.  (If not, you've got a bad
engine-to-body ground.)  Also note if, after disconnecting the sensor, the
engine perks up and runs near normal.  If the engine seems to return to
it's regular character, but the sensor is reading far from 0.5 volts
(especially if it's reading high), odds are the sensor is contaminated.

Running correctly, the plugs should come out with light brown insulators,
and will be fairly black around the body.  Both electrodes should be fairly
clean, with few deposits.  If you're seeing black insulators, and carbon on
the electrodes, you've got a pretty rich mixture.  It sounds like you're
headed in the right direction.


Rich Wagner
Montrose, CO
'82 GTV6 Balocco

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