gcdidthis

So for the second time when it has rained I have gotten a misfire/ rough draft idle and hesitation.

The first time I was was able to hook to a scanner and got Cylinder 7 misfire,cleared it and it's been fine for awhile but with today's rain and it sitting the misfire came back.

I am as always wrench illiterate, I understand but am not the best at fixing things. Where should I trouble shoot?

I have looked at the plugs and cop ends where they meet the plugs and all seem dry and dirty. I tried to look at diagrams to follow the wiring harnesses to what I am assuming will be a coil pack or two. Are they under the air flow assembly on top of the engine or hidden somewhere else.

I did take 2 photos of the only spot that had water on them, again the diagrams didn't tell me what it was but it looked electrical and is right next to fuses.

I did search the forums to no real help and it's raining pretty hard and I'm in south philly so I can't really get at the engine until tomm so I can move it when dry not wanting to go too far with a misfire.

I understand its prob a short as my vw's all did it.

jprevat

iTrader: (1)

Take a look at the firewall behind the passenger wheel well. Your pcm resides there. Make sure water isnt dripping on it.

gcdidthis

gcdidthis

Thanks Jorevat, I will take a look tomm. That it only does it when sitting leads me to think that it's a drip.

jprevat

iTrader: (1)

Thats what im thinking too. The plastic cowl that comes down under the hood has a foam tape that gets old and tears allowing them to leak.

OTG02

Glad I ran across this. Mine does the same thing. Now I know where to look and what to do. Thanks.

Gstran1993

With the boots on the ends of the coil packs being dry and cracked, that could be the only issue, since it's happening when it rains the cracks are allowing the moisture in. You can get those pretty cheap, especially compared to the price of buying a whole new cop. You can swap that #7 coil with a different cylinder and see if it throws a code for the new cylinder you put it on. If you're handy with a multi-meter you can also check the resistance across the primary and the secondary coils.

Jbrew

Post what engine your referring to. You say you COP's , then mention coil pacs. You can't have both lol.

Jbrew

Also post the year. To make sure we get this right.

gcdidthis

It's the one in my sig. 2002 4.6. - thanks for your usual patience JBrew

Not to be semantic but each cylinder gets its own coil pack in effect?

What I was forgetting the name of, was the PCM Module. I didn't get to look today, but will tomm.

I really should have asked "where does the other end of the cable from the plugs end up"

The plugs and cops look healthy, just dry and dirty. I think the PO changed them, and the cables look fine. They would have caused an issue by now, because I've driven in the rain and mud with no issues. Now that I'm off for the winter the truck actually sits for more than a day and it makes sense that it would collect and drip in that spot.