So,
My RX8 started running crappy the last few weeks, but only when it was 90 degrees or more outside. Ran rough. Last week it would barely accelerate to 50 when it was 95 outside.

Same day, I waited till night (65 deg) and it ran great.

So, researching here, I figured it was coils.
So I ordered OEM colis, wires and plugs.

They got here today,
But I got 3 of the N3H1-18-100B-9U coils.
And 1 of the N3H1-18-100A-9U coil.

Question: Assuming the A coil is not as good as the B, is there a better place to use it (Trailing vs Leading)?

 

wow,

with your join date one would have thought you might have provided more info..

like year mileage auto or manual.

but the real quick answer is. the a coil is the first revision. the b coil is the latest.. they all will be fine. and it really does not mater where you put them.

odd that you got a miss matched set. maybe send the a back and get a replacement. and use the old coil on a trailing plug.

btw, it could be a loose wire. or the plugs are old. but you did not give us a clue on that..

after that a vacuum test would be a good idea.

beers

 

OK,
Year - 2004
Mileage 60K (But not original coils. Mazda swapped them out at about 30K)
Manual Tran.

Just was not sure if the Leading or trailing was more critical or stressfull.
Want to get the car back on the road rather than waiting, so I was hoping to just use the coils.

I thought the A coil was actually the seond rev. B coils are the third rev.

 

does not matter what they are. as it seem you are not around here much.

the first thing i would do is go to the dealer and say i have a loss of power..

that sets you into a area where they figure out if you motor is good.. that is the important part.

they should do a engine decarb and vacuum test..

dont let them sell you a thing..

but make sure you plug wires are tight first, and how many miles on your plugs?

i would hold on to the coils as you might just return them. btw, 04 have you had all the recalls done?

beers

 

What does it matter how much I post? I asked a simple question.
Car is out of warranty, so I am doing the work myself.
I ordered the parts online, no dealor involved.

Sorry if this is too complicated.

 

ok,

you are sure it is out of warranty?

lots of things have changed.. if the car has not been updated on all the recalls you have a chance.

but what do i know?

good luck..

beers

 

you are right.

it is not that complicated..

the fact that the 04 warranty has changed twice. and you dont read a lot here, i thought i would ask a prudent question or two. maybe to help you out with the fact that my might have bigger issues.. the fact you did not respond to the recall issue says enough..

so i will give you the answer you asked about. the coils will work the same. put them in either place.

and good luck..

beers

 

OK,
What makes you think I have bigger issues? I just wanted to know if a temperature problem like I am seing is probably coil related. I was holping that being a DIY area that I could get real anserws rather than take it to the dealer .

Also, What makes you think I don't read here a lot. Just because I don't post thousands of times?

 

If you read enough here about the engine bogging down then maybe you would have come across something about bad plugs, bad or loose wires, bad coils, clogged cat, clogged fuel injectors, or even a stuck SSV or AVP. That's all.

You should have your VIN run at the dealership and see if you are actually out of warranty and then make sure all the PCM updates and recalls have been accomplished. Knowing more about the car will go a long way.

 

because i do read a lot. and i gave you a hint, or two or three.

the fact that i noticed when you joined and the last time you posted / activity. i took the time to do that before i answered..

the fact that you never answered how many miles on you plugs or what was the last recall you had done on your car.

you came here for help, but put in no effort. since 05 here or the dealer.

so i guess you and you 60k mile, out of warranty car that does not have any big issues the might have happened a lot since 05, you should google you way out of this..

it is funny, i really tried to give you a hint. and i know the key words that work with the dealers..

btw, i have been posting this all night.

https://www.rx8club.com/new-member-forum-197/rx8-faq-new-owners-116484/

sorry i took the time.

beers

 

Were you getting a check engine light (CEL)? You might have a clogged catalytic converter. Dirty MAF sensor. Dirty Air Filter.

 

I have been reading this sight on and off, just have not bothered to log in for a while because I don't post much.

No CEL..
About 20K Miles since the last deakler service.

Air filter clean, Cleaned MAF.
Again, it only runs like crap when it is really hot outside (90deg). When cool (70) it runs great.

I just figured it was probably the coils or plugs AND they were probably due for a change anyway.

I rally wan't asking for a diagnosis.
My main question was if the 3 100B coils were improved from the 1 A coil I got, if there was a more optimal (leading or trailing) place to use the A coil.

 

They are basically the same coil. I don't know of any technical data released from Mazda on the variables between the two coils. But one is newer and better. So they say. If it was me I would install the "A" in the trailing side.

 

Thanks.

If this doesn't fix my problems I will take it to the dealer.
But, given the temp sensativity to the problem, I really suspect the coils.

Only problem is, not sure we will have more 90+ days this summer here in Oregon to test that it is really fixed.

 

But you are getting one anyway because we have seen this exact same routine several times in the past, we know where it will all end up, and we care about fellow RX-8 owners. Lord knows most dealers don't.

Hot performance isses.
2004-2005 model.
60K miles.

All sounds familiar.

 

Sorry if I sounded snippy (I was a little drunk last night when I posted).

Yes I got your hints, I have done the "It is low on power thing" before (2 years back), and they did swap some of the coils and plugs. Unfortunately, I did not keep track of which ones.

Also, I did recall that they extended the warranty, but thanks for reminding me.
I still wanted to do the work myself IF it is a coil problem. I figure from what I read here , I should get used to swapping OEM coils every 30K miles or so anyway, rather than waiting for symptoms.

 

my first set of coils went 76k miles. my hope for you is you get the last recall done and a vacuum test..

that will paint a real picture.

i hope the coils fix it. really i do. but what if they do and the engine is marginal and should be replaced? and it is covered.

if you need anything send me a pm! i answer all.

a saying i like.

dont fix the blame, fix the problem..


beers:

 

FYI:
changed the coils and plugs last weekend.
Luckily, it hit 93 degrees on Monday.

Car ran great, no stutters or hesitation.
(Now the last time I drove it in the heat it was 96 deg, so I am assuming that this was really the problem.).

 

Oh that's awesome!

Now say thank you to Swoope. :D

 

OK im a little stuck and have pretty much come to the end of my problem solving skills and was hoping that someone else can shed a little light on things.

2003 RX8 80,000km (not miles) SE3P vin, I decided to replace the coils as they were starting to age a little. So i ordered some N3H1-18-100B-9U coils, I replaced these with my old ones and started the car up, all seemed good, i turned it off and then tided up, jumped back int he car to see if the performance has improved. Started the car up and the engine light came on, the Codes were p0351, p0352, p0353 and p0354, my car is stock standard. So i decided this was a little odd, so replaced one of the new coils with my old one and started up, and sure enough i only got 3 errors and not 4, so replaced another and now only have 2, it seems that the 2003 s1 is not compatible with the N3H1-18-100b-9U coils ? or have i missed something ?

Some help would be great or even someone that has had the same issue

Cheers
Gymmy

 

Gymmy, try this thread. It says those codes mean coil circuit malfunction or fault. So it does sound like the coils may be bad possibly? This guy also says he has a 03 rx8.

https://www.rx8club.com/series-i-trouble-shooting-95/diagnostic-shows-problem-coil-c-116592/

 

sounds like you got the coils for the 09 and up..


beers

 

So what coils should i get, the only difference i can see is the following

working .... n3h1-18-100b A1C-1355 0434

not workling .... n3h1-18-100b A1C-1355 1065

All i can see the difference is 0434 vs 1065, other than that its all that seems to be the difference between the coils. They still run the car (well) but the engine light comes on every 2nd time i start the car

A.

 

as my comment, seems you have the coils for a 09 to now r3.

i would bet the ones that are right for a 03 to 08 rx8..

not sure where you are. i have a set, as many others here..


this is just a smart guess, i am sure ash or a parts guy will jump in.

i will say anyone with a 03 to 08 has never got a code for individual coils.. just missfire and front or rear bank.

beers

 

Well thats a pain the a** never mind, ill send these back and see if they can send the correct ones Its kinda stupid that they all have the same part number !

I thought the R3 coils were designed to work in all RX8's as there are plenty of people sending them out there saying that they work on ALL years

Im in New Zealand, I got these from Ebay from Germany as most of the people that post from the USA are asking astronomical amounts for postage e.g. 40$ USD or more.