multiple misfire

I have a po300 randon/multiple cylinder detected misfire, po303 mis
fire cyl #3, po302 misfire cyl #2, po304 misfire cyl #4 that came up
on my emission test. The fuel trim on bank one po170. what advice or
possible fix can anyone give.

In article >,
> wrote:
>I have a po300 randon/multiple cylinder detected misfire, po303 mis
>fire cyl #3, po302 misfire cyl #2, po304 misfire cyl #4 that came up
>on my emission test. The fuel trim on bank one po170. what advice or
>possible fix can anyone give.

When did you last do a tuneup?

What do the plugs look like?
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On Oct 9, 10:48*am, (Scott Dorsey) wrote:
> In article >,
>
> > wrote:
> >I have a po300 randon/multiple cylinder detected misfire, po303 mis
> >fire cyl #3, po302 misfire cyl #2, po304 misfire cyl #4 that came up
> >on my emission test. *The fuel trim on bank one po170. *what advice or
> >possible fix can anyone give.
>
> When did you last do a tuneup?
>
> What do the plugs look like?
> --scott
> --
> "C'est un Nagra. *C'est suisse, et tres, tres precis."

the plugs on the passenger side of the engine was very black with
heavy soot. I changed them but I think more needs to be done.

> wrote:
>On Oct 9, 10:48=A0am, (Scott Dorsey) wrote:
>> In article =
>.com>,
>>
>> > wrote:
>> >I have a po300 randon/multiple cylinder detected misfire, po303 mis
>> >fire cyl #3, po302 misfire cyl #2, po304 misfire cyl #4 that came up
>> >on my emission test. =A0The fuel trim on bank one po170. =A0what advice =
>or
>> >possible fix can anyone give.
>>
>> When did you last do a tuneup?
>>
>> What do the plugs look like?
>
>the plugs on the passenger side of the engine was very black with
>heavy soot. I changed them but I think more needs to be done.

All of them? That's a sign that everything on that side is running too
rich or is badly misfiring. Since it's an injected system, odds are
better that you have an ignition issue or a valve issue than a mixture
issue (mixture issues will tend to be common to all cylinders or specific
to just one). Pull one of the plugs and crank with the plug out and see if
you get a nice fat spark or a thin wavering one.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On 10 Oct 2008 09:47:47 -0400, (Scott Dorsey) wrote:

> > wrote:
>>On Oct 9, 10:48=A0am, (Scott Dorsey) wrote:
>>> In article =
>>.com>,
>>>
>>> > wrote:
>>> >I have a po300 randon/multiple cylinder detected misfire, po303 mis
>>> >fire cyl #3, po302 misfire cyl #2, po304 misfire cyl #4 that came up
>>> >on my emission test. =A0The fuel trim on bank one po170. =A0what advice =
>>or
>>> >possible fix can anyone give.
>>>
>>> When did you last do a tuneup?
>>>
>>> What do the plugs look like?
>>
>>the plugs on the passenger side of the engine was very black with
>>heavy soot. I changed them but I think more needs to be done.
>
>All of them? That's a sign that everything on that side is running too
>rich or is badly misfiring. Since it's an injected system, odds are
>better that you have an ignition issue or a valve issue than a mixture
>issue (mixture issues will tend to be common to all cylinders or specific
>to just one). Pull one of the plugs and crank with the plug out and see if
>you get a nice fat spark or a thin wavering one.
>--scott

Multiple missfire is a good indication that the boot that goes between
your coil pack and the sparkplug has gone bad. You have one for each
sparkplug and they sell for about $11.00 each at vendors like BMP
Design, about $16.00 each at BMW dealers in the USA.

RJD