Kyle Kozubal wrote:
> <snip>Thanks alot for this info, but I doubt having an A/F Ration Monitor
> would
> have solved my problem earlier.
I think you missed my point. Never did I say it would have "solved" your
problem earlier - only that it would have helped you get to the same point that
the dealership is at now (not going into closed loop mode). In fact - I even
told you "earlier" that what you were seeing (steady voltage) from the O2 sensor
(when using another scan tool) was not what you should be seeing - that instead
of a steady voltage, you should be seeing oscillations which are the normal
pattern for a vehicle whose PCM has the system in a closed-loop mode. There are
only 2 things that can cause that - sensors not working properly causing the PCM
to default to an open-loop or "limp-in" mode -or- a bad PCM and/or harness (that
can't "close" the loop in order to "control" the system). The link I sent to
the AutoMeter website even illustrates what a computer-controlled vehicle
"should" look like from the perspective of the O2 sensor. Read up on "control
systems" in general (not necessarily auto-specific) for some background if ya
want.
> I did replace the 02 Sensor with a new one
> about a week ago. Truck was still acting up after that. I took it into the
> shop where they also replaced the 02 sensor, because the truck wont go into
> closed loop mode, and basically stays in open loop all the time. I guess
> this might explain for the rich condition I was seeing on my spark plugs?
> Anyways, the mechanics are still working on it this week trying to determine
> the open loop problem/stall problem. They are just leaning towards a bad
> PCM. How would having an A/F ratio monitor tell me if my PCM is bad?
see above and please keep asking questions if you don't understand as I consider
it a perfect example of how useful the A/F monitors can be. Second only to a
scan tool (I just picked up the GM and Furd versions of mine...only an extra
$62).
Latr,
Shane
-- '96 IndyRam-HisIndy-MPI/TB/Pulleys/AccelCoil/MPComp/HookerSuperComps/CompTAs '96 IndyRam-HerIndy-numbered(#142)"Track Truck" '74 Triple-Black Dodge Challenger Rallye 360 home-brew EFI R&D vehicle '68 Black Corvette Convertible 427 (For Sale)
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