Spark plug arcing?
 

Is this just a sign of the spark plug being shot?
The spark is arcing between where the plug screws into the engine, and the plug wire.
I have a spare set of plugs (NGK), but I'm not sure which are trailing, and which are leading.
Are the blues trailing, and the black leading, or does it not go by that? An illustration might help, if there is an existing one.

Also, do I need a spark plug wrench, or can I just twist it off by hand/with pliers?
Also, what size wrench, and do how hard do I crank it on?

Sorry, I know enough when it comes to the workings of a rotary, but I'm a dunce when it comes to real-world experience.

More like wires either not fully snapped onto plugs or wire is bad. The Leading are 7's the trailing 9's. You can see on the housing there is a cast L for where the leading plug goes. Also I think the trailing has the stripe on the plug. Either way one of the has the stripe so you can see which is which.

Well, I snapped the plug wire off of the spark plug, and snapped it back on.
Still pretty blue sparks.
The car's been sitting for a long time, so I'm finding little gremlins here and there.
Are you sure its not the spark plugs?

If it *is* the plug wire, how do I get the plug wire off of the coilpack? I can't seem to pull it hard enough, and I don't want to break it.

Oh well.

btw--there's no 'L' on the engine, nor any stripe on the plugs. Just blue/black plugs.

btw--I've been driving it for a month now.
It just happened after driving for 45 mins from school to my home.
74F, 1/2 highway, 1/2 city driving.

It's possible that the plugs are bad, but the wires are more likely.

The leading plugs are the bottom set and the trailing are on top (remeber: L=L, Lower=Leading, T=T, Top=Trailing).

I can't remebver which size of plug socket you need, but you can just bring one of your new plugs to your auto supply store and they can hook you up.

You can wrench on the rachet as hard as you need to, as the metal jacket of the plug is pretty solid.

As for the plug on the distributor, most likely is the insulation has gotten itself fused on. It's a fairly common problem with old wires, although it's usually worse at the sparkplug end of the wire. You could try peeling back the insulation from the distributor and then yanking hard. You could also try a little WD-40 to losten it up, but you have to make sure you clean it off the distributor really well after. Then make sure you get a good set of replacement wires.

Hope this helps,
-Spencer

Okay, no problem pulling the plug from the coilpack or the spark plug.
The plugwires are clean as clean can be:confused:
I've got some good NGKs I can throw in tomorrow.
Hopefully, that will fix it all.
If not, its time to buy some new wires.
Wish me luck!

Time to :sleep:

Typically the plug can arc if its cracked from over tightening. Usually they dont crack from heat cause they are ceramic. You will notice the stripe on the trailing plugs. Those are the 9's. The socket you need is a 13/16 i believe. Its good to buy a swivel socket. Make sure it has the rubber gromet inside for plugs. I bought one at pep boys for 19 bucks last year. Made by Stanley I think.

ZoomZoom had a good point, don't overtorque the plugs, and make sure you don't crossthread them either. best way is to put them in by hand first to make sure they're not crossthreaded, then use a torque wrench (if you have one) to get them to between 9 and 13 ft-lbs. If you don't have a torque wrench and can't borrow one, use the ratchet to get them very firm, but without wrenching on 'em too hard. then back them up 1/8th of a turn. that should be pretty close.

That's what I did
Fred Meyers: $10 3/8 handle, $4 13/16 spark plug socket
Works fine
It was the spark plugs.
They were the original plugs (90k miles)!
I just got this car a month ago, so..Wasn't my fault:rolleyes:

Ouch! That's a lot of wear and tear. You might want to consider replacing your wires too then, since they are most likely also original. They're probably as bad as the plugs were.

Have you replaced the fuel filter yet? Most likely it's WAY too old.

:)

Nope. Maybe I should.
What's best, Mazda OEM, or K&N/other alternative?

The OEM is fine, but the K&N is better. Either way as long as it's changed on shedule, and you should be good.

How old is the oil and filter?

-Spencer