Hello I have a couple of questions.

First off my idle dips 100 rpm or so and causes engine to vibrate and I have read that it is due to failing ignition system so im going to buy my spark plugs. I was looking at buying at NAPA auto parts but on their site everything matches OEM but they dont have the RE7C-L and RE9B-T numbers, so are these okay?http://www.napaonline.com/Search/Res...+50042+2042031

Second, what is the difference between the 8.5 mm and 10 mm spark wires?

Third, when I rev the engine from idle to 7k then just let go as it decelerates the exhaust pops or has breaks in the exhaust note, im guessing this has to do with ignition going bad?

Car is a 06 RX8 with 61k miles. I have owned it since 57k.

Thanks.

 

Okay real quick like I will answer these and then let others follow-up.

Yes, the plugs will work, but........since you may or may not know if you are still on the original coils, I would change the coils as well. Having said that if you can afford to wait a few days, I would buy them as a set from one of the vendors on this site. Go to the vendors section!
There you can find vendors and get all three(coils, wires, and plugs) in one shot, at a discount over most places, and know for the most part you are getting what you need. You could even go for a new ignition system.........don't miss BHR for this. http://blackhaloracing.com/products-...gine/ignition/



Second question, the difference is about 1.5mm
Sorry, but I had to do that.
Lots of variables....quality, components, but all things considered(and the rest of this is just my opinion), you really don't need larger than 8.5mm. 10mm cable has a thicker insulating jacket, and usually designed for extreme heat situations or where extra insulation is needed for extreme-output ignition systems and where it's not easy to space the wires from one another and/or the engine. Most street and modified production engines don't really need a cable size larger than 8.5mm, using 10mm size cable is usually overkill for the most part.

here is another option if you want to stay with OEM. You will find coils and wires here as well, but it is only one of many palces! http://www.racingbeat.com/FRmazda4.htm


Third question is a little tougher without hearing it. I will say that the exhaust note does change when you do that and may give a little pop, that's not unusual in my opinion.

 

On the exhaust note it seems to be doing it more than one little break. It does it multiple times and it sounds like it does it consecutively, say every 1k rpm going down it breaks in a pattern.

On the coils I forgot to mention I was planning to buy the coils next paycheck which is next week and just do the plugs and wires this week.

 

Suggestion:

You are about 4K miles into this relationship. Check out the link in my sig. It also points to a new and prospective owners thread. I did plugs and coils as well, but things did not settle completely until I took care of the grounding stuff in those posts.

Good luck.

Mike

 

I did some edits, might want to re-read my post.
Gotta run out......sorry.

 

I pretty much got all of that on my car done already. The previous owner took care of most of that. After I do ignition next on my agenda is coolant flush, Clean TB and MAF, as well as Seafoaming to make sure everything is in tip top shape.

Already changed Diff and Tranny oils. The dealer I bought it from I found out that I shouldnt trust so im doing all maitenence. They tried to sell me her with bald rear tires and they changed two tires and they didnt balance them as well as mixed high performance tires with all season tires...still pissed about this

 

I would look at MAF first. If it was that well cared for, might have had plugs and coils done. MAF is not something usually looked at. Far cheaper than plugs and coils. So far, MAF clean has made an instant difference on every car I have tried it on.

 

Yeah im thinking the MAF too with the problematic idle, I mean it only dips 100 or so RPM but from time to time, actually twice it almost went to the point of dying.

 

Yeah, but while you are in there, look for a small vacuum leak as well. Something like one of those plastic elbows on the accordian tube being cracked or something. It will be small, but could be that as well. MAF should be on the list as stated before, that's an easy one.

 

This is the best 28 post member ever! Nice wheel color too.

 

Haha thanks. I just painted my stocks. Next purchase is some wheels. Lol

 

so an update, NAPA only does our plugs on special order, and they will make you buy 4 leading and 4 trailing because they cant buy 2 of each and they dont want to stock the extras. Really dumb if you ask me.

So im just going to buy all the parts next week. Race Roots is good vendor yes?

 

Vendors here sell plugs all the time so that's not a big issue!
As for Race Roots being a good vendor just do a search in the good\bad guy forums at the bottom of the board!
A couple of links to save you some time: https://www.rx8club.com/good-guy-bad-guy-74/race-roots-coming-clean-195840/
https://www.rx8club.com/good-guy-bad-guy-74/mazsport-race-roots-minds-eye-engineering-195827/
https://www.rx8club.com/good-guy-bad-guy-74/raceroots-feedback-190659/

 

Yes, Race Roots is very reputable and you'll be supporting a company that cares about our car and it's development.

 

wow, if I didnt look at this guys posts, wouldve never guessed he was new to the forum lol.

Sounds like your cars on the right path. My car dips in idle when I flip the AC on, or on hot days sparatically with minimal vibrations. Mine has done this for all 82K miles of it's life, whether it's normal or not, I have good compression and good coils and no vac leaks. So it MAY be normal, however new coils, a clean MAF, etc will definately smooth it out quite a bit.

 

Haha yeah I barely posted on the forums because I was just here reading all day to know my car inside and out, thats what I did to my WRX when I first got it.

Back on topic it doesnt change with AC on and does it all the time. Hopefully doing all of that will help it out. Just waiting on my spark plugs, wires and coils.

 

Should help at least somewhat.
Yeah.....wish everyone would do that. I did nothing but read for like three months solid when I first got the car. Actually read up a few weeks before I got it as well.

 

Exhaust pops can be normal. Depending on mods to the car. Stock I didn't notice them at all...with my catback I could hear them...and now with a midpipe I can feel and see them. For the most part I would consider it normal and not worry about it much unless you start feeling other issues coming along with them.

 

Yeah I was the same way. Joined the site in may. Read since lol

 

Reviving my thread for the people that were following it. Finally got to replacing my plugs and wires. She runs a lot better now, low range power came back. Coils are happening at the end of this week once i get them in. As well as Throttle Body cleaning and MAF cleaning. Sidenote Plugs were much easier to do than I thought, my WRX they were worst than this. My old plugs are burnt so im guessing they were never changed, must do coils now.





To my idle dipping problem hopefully it is cured after MAF and TB are cleaned. Or maybe my idle dips are due to a vacuum leak, I found this open vacuum line in front of my airbox, can someone give me insight on it because it is just left open there. Im thinking that could be part of the problem to my idle dips. Thanks guys. We stuck a screw in the open hose to temporarily close it until I figure out whats up with it.

 

Could be part of the VFAD lines, plug the one at the bottom right of the TB.

 

its weird too because theres a clip thats holding it there.

 

The plugs have pretty normal color.

You can track the vacuum lines from this drawing, marked up by Jon316G and modified by me

 

Yeah their all burnt, Thanks for this diagram, ill try to hunt down which vacuum line this is. According to this it does look like it could be to the VFAD. I have read that a lot of people delete VFAD? which makes me think my previous owner probably did since he put K&N drop in filter and took out the little walls in the air box.

 

Im having trouble finding which line is the VFAD line. Here is a pic on the side of the throttle body.