RE: Bad Knock Problem was:Misfires -- STILL NEED HELP!

From: Mok, Alan (SPB) (AMok@spbank.com)
Date: Sun Jan 24 1999 - 00:04:27 EST


Did you get 2 wires crossed? If not, I would put the old plugs in and return
it to the exact same configuration as before the problem. Maybe you got the
wrong plugs (heat range, etc.).

        -----Original Message-----
        From: fawcett@uism.bu.edu [SMTP:fawcett@uism.bu.edu]
        Sent: Saturday, January 23, 1999 2:55 PM
        To: dakota-truck@buffnet.net
        Subject: DML: Bad Knock Problem was:Misfires -- STILL NEED
HELP!

        O.K. I misdiagnosed this... What I thought was a misfire is
actually heavy
        spark knock. It was very intermittent on a mild highway incline so
I found
        a steeper incline and I'm still nervous after what happened. I had
the
        cruise pegged at around 65 or 70 and about half way up the hill it
started
        to knock really badly... Before I could pull over the check engine
light
        (MIL) started to flash rapidly (limp-in mode?!) and the engine was
running
        incredibly rough --almost like it was going to stall at around 50
MPH! I
        got over into the right lane, switched the O/D off and was able get
up the
        hill and off the highway... The check engine light stopped flashing
as
        soon as I got off and has not come back on since. Man, I thought I
had
        really screwed up my Kota!

        I got back home and yanked every plug and checked the gaps as best I
could
        with these Bosch +4's... They have four ground electrodes so it's
kind of
        hard to check but they all looked consistent... The only thing I
found was
        a slightly higher carbon buildup on the plug in #3 cylinder and the
#5
        cylinder plug looked like it had never been fired (no carbon
whatever).
        All the others looked fine.

        I checked all vacuum lines and wires and everything seems OK... I'm
also
        running the Magnecore 8.5mm wires which seem fine. This is the
first V8
        I've ever owned... With the V6's, straight 6's and 4 bangers I've
worked
        on it's been obvious as soon as you start the engine if one of the
plug
        wires is shot (or you connected them wrong)... Does a V8 still run
smooth
        with only 7 cylinders firing??

        Is there an easy way to check if a plug wire is good or not? Any
ideas on
        what the heck is going on??? At a minimum I'm gonna' run out
tomorrow and
        get some dielectric grease 'cause I did not use it. Any other
suggestions?

        Thanks!

        Tom
        ______________________________ Reply Separator
_________________________________
        Subject: Re: DML: Misfires -- Need Help
        Author: <dakota-truck@buffnet.net> at smtpout
        Date: 1/23/99 3:52 PM

        You may have damaged the spark plug wires when you pulled them off.
Did you
        have to wrestle to get them off? I've had this problem on 2
different Daks. On
        1 of them I had to pull the wire off the plug by bits and pieces.
USE
        DIELECTRIC GREASE ON ALL CONNECTIONS AND ON THE INSIDE OF THE BOOT.
        Dr. Pat
        ----------
>From: fawcett@uism.bu.edu
>To: DAKOTA-TRUCK@buffnet.net
>Subject: DML: Misfires -- Need Help
>Date: Sat, Jan 23, 1999, 2:06 PM
>

>I installed the Bosch Platinum +4's this past Monday and I noticed
what I
>think were several misfires at high speed -- about 65-75 MPH. It
happened
>going up a very slight grade with about 1/2 to 3/4 throttle (auto
tranny
>did not downshift or come out of O/D) and does not seem to happen
at WOT...
>
>My truck is a '98 318 with ~10k miles on it so I don't think it's
the coil,
>distributor, fuel injectors or other stuff that can cause this. I
did put
>my FABM 10" back on at the same time I put in the new plugs and I
did reset
>the computer...
>
>Is it possible/probable that the computer just needs more time to
adjust
>and I should just wait this out or should I just go ahead and start
yanking
>the plugs and check gaps (even though they were "factory
preset")??? Is
>there a better way to diagnose the cause of a misfire?
>
>Thanks in advance for any help.
>
>T.
>
>P.S. I wrote to Dave (Fish) who also recently installed these
plugs and he
>does not have the same symptom/problem... Thanks for checking for
me Dave!
>
        



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