Jamie C <jamie12ga@gmail.com> wrote:
> On Sun, May 8, 2011 at 9:28 PM, <jon@dakota-truck.net> wrote:
>>
>> Jamie C <jamie12ga@gmail.com> wrote:
>>
>> > Bill,
>> > I did some Googling and most of what I came up with stated that EGR was
>> only
>> > up to '95. I know I have egr (tube from intake manifold to exhaust
>> > manifold, transducer/valve, canister by passenger fender, etc). And it's
>> a
>> > '96...has an OBD II PCM (silver metal PCM, not black plastic OBD I PCM).
>>
>>
>> Interesting. The rectangular metal box with 3 connectors, right?
>> I wonder if there was some sort of parts mixing during the changeover?
>> That would be weird, but I've learned "never say never" when it comes
>> to Mopar!. Do you happen to know your Dak's build date? If not, and
>> if you still have the decal on the driver's side door, you can get it
>> from there. Here's an example of what a Jeep decal looks like, should
>> be similar on your Dak: http://www.steigerperformance.com/libertybuilddate
>>
>> > What was changed on later 3.9's, 5.2's and 5.9's to be able to run
>> without
>> > egr?
>>
>> I believe they just removed all of the EGR crap and the computer
>> does not look for it.
>>
>>
> Yes, 3 connectors to the PCM.
> The build date is 11/95. I guess they had some exhaust tubes, transducers
> and canisters to use up!
That's interesting! Mopar has done some goofy things over the
years, which is why I "never say never" when it comes to some of the
different ways these vehicles can come out of the factory.
So I guess the question is, if they were indeed using up some of
the leftover '95 parts, did they actually enable EGR in the computer?
Because as far as I know, the '96 vehicles' computers know nothing
about EGR. It wouldn't seem to make sense to put the EGR stuff on
there if the computer wasn't actually going to use it (seems like it
would be better just to transfer all of the leftover parts from the
assembly line to dealer inventory to use for repairs on existing
vehicles, rather than just "wasting" it by installing it on vehicles
that aren't even going to use it.) If they were trying to use up the
exhaust manifolds and/or intake manifolds, why not just block off the
ports?
Here's an experiment you might want to try... (Might have to wait
until you actually get the engine rebuilt and reinstalled though.)
Unplug the EGR valve's electrical connector and see if the truck ever
complains about it. Another thing to do might be to try and trace the
wires from that connector and see if they ever actually make it to the
computer.
Do you have the OBD-II data port on the underside of the dash in
the driver's side footwell?
Here's another possible data point... I just did a search for an
EGR valve on one of the Mopar parts sites that I often use, and its
showing the application years for the EGR valve to be 1994-1997 for
the 3.9, 5.2 and 5.9. (1992-1997 for the 2.5) Granted, that could be
a typo, but it also might be an indication that some of the OBD-II
trucks were actually supposed to get an EGR valve.
One thought that comes to mind is I wonder if this could have
anything to do with the Federal vs California emissions packages? Do
you know where your truck was originally sold? I wonder if the CA
emissions trucks had EGR but then at some point they realized it
wasn't necessary and dropped it?
Here's another data point - I just looked through my 1996 FSM and
could not find any reference to EGR at all. Also, in the diagnostic
trouble codes section, it skips from code 31 to code 33. (code 32 is
EGR). The PCM connector pinouts list nothing for EGR, though there
are some unused pins. This makes me wonder if they really were just
using up parts. I have a strong suspicion that your EGR system is
actually doing nothing at all! If you have an opportunity to trace
the wires from your EGR connector, I'd be highly interested to learn
where they connect to, if anywhere! If they do actually run into the
PCM, I'd be interested to learn exactly which connector and pin it
goes to, to compare to the pinouts in my PCM.
Strange things are afoot at the Circle K. :-)
--
-Jon-
.- Jon Steiger -- jon@dakota-truck.net or jon@jonsteiger.com -.
| '96 Kolb Firefly, '96 Suzuki Intruder, Miscellaneous Mopars |
`-------------------------------- http://www.jonsteiger.com --'
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