Possible Plugs And Wires?

[95Stangpa]

On my SN95 3.8 V6.

Installed my TPS and all has been perfect, was very happy for a week.
Today I noticed the idle was a bit rough, and pulling out seemed like a miss going on. Pretty rough miss!! So i put it back in the driveway.
The last 4 days have been fine until it poured down rain. Not that my motor is getting wet sitting still, but I'm thinking the wires??
I went and restarted it a few hours later and it didn't do it?? Smooth after that....Wth???

I may change the plugs and wires they look old... I seen Denso and NKG...Is on better than the other?
I know some cars don't like certain plugs.

Does this sound like a plug/wire issue??

My TPS is not adjustable. No slotted holes. When I installed it, the CEL went out and it ran perfect. A week later, now this....

 

[General karthief]

A tuneup is good, just regular plugs/wires, don't be fooled by fancy ads that you'll gain any power from using a plug made with molton lava based material dipped in gold. Your 3.8 just needs new stuff, not fancy stuff.
After the tuneup, disconnect the negative cable on the battery for 20 minutes or so, take it for a ride to get everything up to operating temp then check codes.

 

[95Stangpa]

I have no check engine light which is a good thing. I just took it for a quick ride and it's running perfect.
However, there's no rain today it's very sunny and hot out. It's seem to do it when it was pouring down rain and got Damp out. Which tells me probably wires.
I wasn't sure from Advance Auto online when I was looking which spark plugs I should be putting in it. I should've explain that better. Like some of them don't like the platinum's, some like the old copper. Stuff like certain ones. I know some can be a little picky with what plugs they like.
They have Denso Platinum, Denso Iridium, Bosch, NGK... there so many to choose from it's crazy I just want to normal spark plug. LOL

Although I did see
Motorcraft Original Equipment Finewire Single Platinum??

Would that be close to factory?

 

[General karthief]

Yes

 

[95Stangpa]

Thank you that's the ones I'll buy.

 

[jozsefsz]

I've had similar with wires, a cracked plug (when you're standing on your head to change them sometimes you manage to crack one if the wrench slips), and sometimes the coil pack cracks on the bottom when the epoxy gives up and you'll get arcing. If it's not the plugs & wires (probably is), the coil pack's worth looking into -- just take it off and look for carbon traces where it's been arcing on the underside, usually following a crack in the epoxy. But yeah, the moisture in the air (nothing has to get wet) can cause these types of symptoms with an ignition fault, and it'll clear up when it warms / dries up. I think you're on the right track.

 

[95Stangpa]

Thank you very much I will check out the coil pack. I didn't know how hard it was to get the plugs yet I didn't really pay much attention. I finally pried my car back off of my wife.

Yeah I was all excited when it was running good again, it's been dry and warm now. It's just a miss when it's damp out. My brain went to wires, but will check the coil pack for sure.

When I bought the car my buddy looked and told me you might want to replace those plug wires. I think he caused me bad luck. LOL

 

[95Stangpa]

I finally got a chance to pick up my plugs and wires today. I'm going to be doing them tomorrow.

I bought the Motorcraft spark plugs and ask Advance Auto parts while I was there but my gap was since I don't have a book yet. They told me .054, I'm verifying that that's correct?

The reason is, he was looking at the other spark plugs like NGK, Denso, and it showed a different gap for different brand spark plugs. I've never heard of such a thing.

 

[95Stangpa]

OK I change my plugs and wires. Actually they must've needed done because the car ran so much smoother and idle.
Since it's not raining here today I took a spray bottle, and misted the top of the coil pack and immediately it started misfiring really bad.
Just like that day when it rained out, although it didn't get rain on the car. Just a damp condition.
I guess I need a new coil pack? I guess I'm basically answering my own question, just making sure.
I basically just misted the whole top of it. Immediately you could see the engine start chugging.
Is this something common on them? At least I don't feel as bad.
Or maybe Did I spray too much water at it it by accident and I over did it? Just a typical windex spray bottle with heavy misting.

 

[jozsefsz]

Personally I'd change the coil pack even if I wasn't 100% sure. After 20+ years plastic and epoxy will have some problems - it only takes one over-tightening to damage it as well. Light misting shouldn't cause a misfire. You could always watch for fireworks after dark and see where it's arcing, but it sounds clear that it is. I've been through 2 of them on my 2001 Windstar (same engine though they buried the coil pack up by the cowl and it gets heat-soaked and wet from the cowl too). I swore it couldn't have been the coil again the 2nd time and went on a goose-chase but sure enough it was the coil.

 

[95Stangpa]

Well I remove the coil pack. I couldn't find the cracks but I don't think that matters.
That 4 prong connector that plugs on to it, it's broken.
I can put some pictures up on my photo bucket later tonight but it's missing a piece half way around on the cool pack connection of the plug.

But also the connector that plugs on to it is broken also.

So I don't know if moisture getting into that for 4 prong connector can cause a misfire?? I don't know what that connector really is.

I see Advance Auto sells the new connector and of course the coil pack.

The only difference I see is the Colors are different on the wires as opposed to my car. So I guess I'll have to just be cautious while rewiring the connector. I'm just guessing that's what the issue is.

Just trying to verify if moisture gets in at four prong connector can cause misfiring?

 

[jozsefsz]

It can definitely cause misfiring. On the coil pack there are basically 3 twin coils that fire at the same time. So the 4-wire plug is one hot (+) wire and 3 negatives. Basically like 3 old fashioned coils mashed together. Any moisture in there can cause a cross-fire or a failure of the energizing power for one or more coil-sets to go straight to ground.

 

[95Stangpa]

It can definitely cause misfiring. On the coil pack there are basically 3 twin coils that fire at the same time. So the 4-wire plug is one hot (+) wire and 3 negatives. Basically like 3 old fashioned coils mashed together. Any moisture in there can cause a cross-fire or a failure of the energizing power for one or more coil-sets to go straight to ground.

Thank you for the help. I didn't know if that plug could cause misfiring or not. I did see it had a rubber ring, like as for sealing it. So I figured it didn't like dampness.

But you just verified my issue, at least I know what my problem is now.

My car connector has 3 yellow wires and one purple, the aftermarket connector has one red and three black. I guess if I have the plugs faced the same way, I can just match the order of the wires to connect them. Did that make sense? LOL

For your entertainment, heres the photos. I feel stupid, but I wasn't sure if that could cause a misfiring so horrible!

Soon as I sprayed the top of the pack, if felt like a high lift cam. Without the fun!! Someone truly hacked when working on this car. People amaze me!

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