This morning I have a very rough running engine and the check engine light. I stopped at Autozone to get the code read and got code P0301 (cylinder 1 misfire). I bought new spark plug cables and tried changing just the cylinder 1 cable- no change.

Eventually I started unplugging the cables one at a time right at the coil pack and letting the terminal just dangle right near the normal connection point, but separated by about an inch or so. Every time I did this, I got a good spark jumping from the terminal to the spark plug cable, except for position 1. No spark at position 1.

I ohmed the coil pack and obtained the following readings (see below):

http://home.kc.rr.com/bnpndxtr/download/coilpack.gif

Note positions 1 and 5, and the differences in the resistance readings compared to the other positions. It is interesting to note that 7.4K + 14.6K = 22K, such that the resistance to ground measured at terminal 5 is probably completely due to a path thru terminal 1 to ground. So it looks like terminal 1 has 7.4K to ground, while all the others are essentially open circuit to ground. So this further makes me think the coil pack is bad at position 1.

Anyone else see something like this?

Thanks,

Brian

 

>This morning I have a very rough running engine and the
>check engine light. I stopped at Autozone to get the code
>read and got code P0301 (cylinder 1 misfire). I bought new
>spark plug cables and tried changing just the cylinder 1
>cable- no change.
>
>Eventually I started unplugging the cables one at a time
>right at the coil pack and letting the terminal just dangle
>right near the normal connection point, but separated by
>about an inch or so. Every time I did this, I got a good
>spark jumping from the terminal to the spark plug cable,
>except for position 1. No spark at position 1.
>
>I ohmed the coil pack and obtained the following readings
>(see below):
>
>http://home.kc.rr.com/bnpndxtr/download/coilpack.gif
>
>Note positions 1 and 5, and the differences in the
>resistance readings compared to the other positions. It is
>interesting to note that 7.4K + 14.6K = 22K, such that the
>resistance to ground measured at terminal 5 is probably
>completely due to a path thru terminal 1 to ground. So it
>looks like terminal 1 has 7.4K to ground, while all the
>others are essentially open circuit to ground. So this
>further makes me think the coil pack is bad at position 1.
>
>Anyone else see something like this?
>
>Thanks,
>
>Brian

Hello Brian,

I'm currently going through the same problem you appear to be going through. My p/u was also diagnosed with the same code that you have.
Have you already replaced the coil pack, and if you have, did this fix the problem?