Just recently replaced plugs and wires, bought them from one of the vendors here.

Problem is new wires don't have mark on them so I can't figure it out if it's for leading or tailing. Two have BLUE END and the other TWO have BLACK END. Which one goes for which?

And HOW TIGHT do you tighten the plugs??
I've seen, reading all dIY's but not sure what it means when it say torque specs whatever. I just tightened with torque rachet till it feels like tight enough.

Any comments welcome!! HELP A NOOB HERE!!!

 

I mail-ordered the NGK plug wires a while ago but have not installed them yet. My two blue-end wires have a "1" sticker and my two black-end wires have a "2" sticker.

However, it seems to me none of that matters. Seems like what matters is to make sure the correct IGNITION COIL goes to the correct spark plug, whether leading or trailing.

Isn't that right? Am I missing something? Someone else chime in?

EDIT: I reported the number stickers incorrectly. One blue wire is numbered "1" and the other blue wire is numbered "2". One black wire is numbered "1" and the other is numbered "2". The "2"'s are longer than their respective "1" counterparts. However, both blue wires are longer than both black wires.

So it seems to me that the 2 black ones are meant for the spark plugs of a particular rotor and the 2 blue ones are meant for the other rotor. But the question remains concerning which numbers (1 vs 2) to which spark plug (leading vs trailing). Could you try to match lengths with the wire set that came with the car?

 

I read from one of the DIY's on here trailing plug wires have mark on them and when you replace it, you have to make sure they match otherwise you are f#@ked...

Same as mine, two of them have "1", the other two have "2".
Anybody else done it before?

 

The shop manual talks of the wires to the trailing plugs having blue tape and green tape. If the wires are different lengths, that would give a clue as to which is which.

The shop manual gives the torque spec as 114 to 156 inch-pounds. Hope you put some anti-sieze on the threads.

Ken

 

Thanks, I will be working on my car tomorrow.

 

I just double-checked my NGK wire set. I was wrong about the numbers.

As I have noted in the edit in my post above, I originally reported the number stickers incorrectly. One blue wire is numbered "1" and the other blue wire is numbered "2". One black wire is numbered "1" and the other is numbered "2". The "2"'s are longer than their respective "1" counterparts. However, both blue wires are longer than both black wires.

It seems to me that the 2 black ones are meant for the spark plugs of a particular rotor and the 2 blue ones are meant for the other rotor. But the question remains concerning which numbers (1 vs 2) to which spark plug (leading vs trailing). Could you try to match lengths with the wire set that came with the car?

 

The blue and green tape are on the OEM wires that come with the car. Just to clarify, people on this forum (e.g., nycgps) have asserted that the NGK wires ARE the OEM ones. However, you can buy the NGK wires for about half the price of the OEM ones.

Also, the NGK wires don't have green/blue tape, at least mine don't. There are no color codes distinguishing the NGK wires, as far as I can tell.

 

That's how I did it, and thinking maybe I did something wrong since the idle problem is not going away. They weren't exact, but close enough. I will re-check everything tomorrow and let you know. Thanks man.

 

Oh I didn't know you had an idling issue. You've replaced wires and plugs, so looks like it's down to replacing ignition coils and going from there.

Also, I didn't answer your question about tightening spark plugs. I heard from several experts that you don't need to use a torque wrench to tighten spark plugs. In fact, they prefer not to. Instead, you use feel. You go to the point where it just/suddenly becomes tight and feels like you can go just a little tighter but then you back off a little. I've done my spark plugs twice using that method and I'm confident I did it right. It's hard to explain it; you just have to do it and "feel" it.

 

Don't know about the backing off, but that's the way you can tighten plugs that come with a crush washer.

Plugs can come with three kinds of washers: plain copper rings, crush washers, or a tapered seat and no washer. With crush washers you can tighten by feel. The sudden tight feeling is when the washer has crushed all the way. Copper rings and tapered seats can also be done by turning a certain amount after first contact.

IMHO, if you're not a mechanic doing this every day, it's prudent to use a torque wrench.

Ken

 

 

Nice after-sale support from the vendor(s) in question.

 

Hmm. I'll use a torque wrench next time then.

 

Looks pretty straight forward with this picture.

Plus you should have replaced the plug wires one at a time and compared it to the new set of wires and picked the closetes match.

Common sense......

 

That pic is irrelevant. That's not the issue that the OP is talking about. With the NGK wire set, two wires are blue (one marked with a "1" and the other with a "2")and the other two wires are black (one marked with a "1" and the other with a "2").

The OP is not sure but he thinks he read somewhere on this forum that one pair of wires is designed specifically for the trailing plugs and the other pair is designed specifically for the leading plugs. So FIRST, the OP would like clarification whether or not this true.

SECOND, if true, then what is the indicator for whether a wire is for the leading plug or the trailing plug? Is it by the color or by the number? By my deduction, it would go by the number. But then, which number (1 vs 2) for which plug (leading vs trailing)? Again, this is IF in fact there are two differently-designed wires.

 

Here's how my NGK's are installed:



Blue, black, blue, black. The factory plug set had two that were completely black, and two that had other colors on the boots. The ones that had other colors on them were the trailing plug wires. For the trailing I used the NGK wires that had black boots (instead of blue), and for the leading I used the NGK wires that had blue boots on them. They all fit PERFECTLY this way and I've had zero troubles with them.

Here's an image that shows the leading/trailing plug wires and how the trailing wires have the different colors on the boots that I spoke about. Notice the blue/green stripe on the boot:



Hope that helps!

 

Pretty simple: NGK is using colors black and blue to indicate 'lead' and 'trail' positions, while the 1 and 2 represent Number 1 vs Number 2 rotor housings (Front vs rear). One super easy way to remember lead vs trail is 'lower' vs 'Top'. The L and T are written on the housings as shown by RWatters.

Paul .

 

If for any reason your NGK plus didn't come with a 1 or 2 on them, I believe one set of the wires is actually a little longer than the other as well. The lengths when installed should be PERFECT to each plug. No wire was too long or too short for each plug when I installed them.

 

So considering what Paul just wrote, then I was wrong about color vs number.

But simple? LOL. I don't think a lot of the people are considering all the permutations.

 

I've never installed plug wires on an RX-8 before until I ordered those NGK's and I picked it up right away. The only thing I needed was a picture that showed the best way to route the wires down to the plugs themselves.

What sent me for a loop was pulling out the spark plugs on my RX-8 and noticing that all four were leading plugs. That was a bit strange to see. Me'thinks a dealership screwed up installing some replacement plugs somewhere along the way with this car!

 

Thanks for the replies! Got mine installed, had to double check and etc
found out that 2 plugs aren't going in all the way, they were going in crooked,
NOT STRAIGHT!!!

I had to raise the car up three times already and where I live, it's 100 degree out side and I gave up. I will drop my car off tomorrow at the dealer stealer.

See how much they gonna rape me, lol.

 

It's not about understanding it right away. When you say that, like Razz, right away I know you don't understand. That's why I've said repeatedly it's more complicated than you guys have assumed.

It's not about matching wires according to the manual's diagram. The issue is IF there are two differently-designed wires (i.e., two are for the leading plugs and the other two are for the trailing plugs), then how do we know which two are which? Do we go by color (blue vs black) or do we go by number (1 vs 2)?

THIS QUESTION STILL HAS NOT BEEN ANSWERED. It looks like we can render this question moot by just following Paul's instructions. For logic aficionados, even Paul's instructions do not indirectly tell us the answer. His instructions could imply two differently-designed wires OR it could imply another factor, such as wire lengths.

 

I'm showing my age a little when I make the following statements: Mazda has used the same labeling since the beginning (1967, which is before I was born barely). The 1 and 2 are first and second housings, front and rear. The colors represent lead and trail. The wires, like any other car are of different lengths in relation to their positions. They are not different in any other way. Their labeling relates to their length and make it easier to ensure you have the correct coil going to the correct plug.

I NEVER like to be insulting and I'm not starting now. Please take this as a kind helpful hint: If you aren't versed with tightening things, torquing bolts and the like, I strongly recommend that you take your car to someone trained to handle this stuff. A loose spark plug, an overly tight spark plug or worst of all a cross threaded plug can be a nightmare.

I grew up doing plugs and wires on piston engines as well with distributors including points and condensers with an oscilloscope to observe how properly everything was functioning. It's fun to do a tune up on a dual bank engine considering timing order, direction of rotation etc.

My thoughts are not intended toward ArXate but to all that care to pay attention: We all don't need to be mechanics!

Paul

 

Go by color and use a little common sense. Mazda had two plug wires that were one solid color, and two that had additional colors on them. NGK provides two plug wires that are one solid color, and two that had additional colors on them. Mine didn't have 1 or 2 on them. They were all taped together in an NGK box and that's it so apparently it's not all that important.

You say I don't understand, but here's what I do understand:

The plug wires are on my car, they fit perfectly, and my car has run like a champ for the 2,000 miles they've been on there. No CEL's, no misfires, no anything. I don't think it's making a stretch to say that I did it correctly.

I think you're taking something rather simple and trying to turn it into something that needs a rocket science. Apply basic logic based off of your observations (and instructions in this thread) and see what happens. If your car doesn't run well then take them off and try again. If it STILL doesn't run well then put the stockers back on and take it to a shop.

If this comes across as rude that's not my intent at all, I just believe you're making this far more complicated than it actually is.

Out of curiosity have you called NGK to see what they say? That might be worth the effort.

 

Remember, I am trying to find the answer to an issue brought up by the OP, not by me. One thing I'm known for is being very good at "seeing" and expending the energy to see what other people are seeing (and trying to describe). I am also known to be extremely meticulous when researching literature, texts, and articles, and this includes reading other people's posts.

Please note the above quotes. Paul states that the NGK wires use black to indicate leading and blue to indicate trailing. In contrast, RWatters states he (for the NGK wires) used blue for leading and black for trailing! Did anyone else catch this discrepancy? LOL.

So this outcome brings to light- and vindicates me for- what I've been repeatedly trying to say, that it's not that simple. If there is no mistyping by Paul or RWatters, it appears color is not an indicator (meaning color does not indicate anything critical, such as if there are two differently-designed wires, one for leading and one for trailing). Rather it could be that color is just a "helper" to help the installer keep track and stay consistent. And if the latter is in fact the truth, then this is the only situation that is simple.