Anyone replace ignition coils yet?
 

Just curious if anyone has had any issues with them so far? If you got the BHR coils just to upgrade that wont count unless your coils died first. :P


I am at almost 35k miles and get a rough/hunting idle when sitting at stop lights. Usually goes between 750 and 1100 when it hunts but I have had it go down to 500 and then shoot up to 1500. Since a few months ago I replaced my spark plugs I figured coils + wires might be the next thing that will hopefully cure this from the posts I have read.

My car is at 40,000 miles now, and I've gradually noticed my idle quality is not quite perfect anymore. It does not appear to hunt or misfire, but there is a bit more vibration when stopped in Drive unless the weather is warmer and the engine has been running quite a while. Fuel mileage isn't bad, but might be down maybe 1 mpg overall according to my scangauge. Plugs were replaced at about 30,000 miles and did not improve the idle quality. So, I've ordred a set of coils and will see if there is any improvement.

The normal thing to do with the 8 is to change the entire ignition system at once ie coils, plugs, and wires. If one fails it's a good bet they're all gonna fail or are about to.

Yea I was just kind of curious to see if the s2's were holding up any better with the different coil mounting plate. There was some talk about it having a little spot for air to flow under the coils and that it might improve their life but so far it is not looking like it. I don't really think I need to replace the wires also, but they are so cheap for oem ngk ones($22 at rockauto) I might as well.

Well, just changed my coils + wires today. The coils all had a pretty large white spot developing on the bottom and wires looked kinda bad on a few spots as well. I know people say the white spot isn't a good health test.

I went for a drive afterwards not very far maybe 8 miles and there is a noticeable difference. Seems to be easier to start accelerating from a stop now, and my idle is now solid at 950.

Interesting. So the idle quality improved? I don't think my idle has ever been 950, even when new, but then I'm going by the ScanGauge reading so there may be a difference.

I am going by just the needle. I am only 8 miles into the drive and I assume there are some things the car needs to re-learn after the battery cable is off for so long. Maybe the idle will return to being bad I don't know. As for now its perfect, no more constant dipping down jumping up when at idle.

Edit:

I don't know how bad my coils were, but after driving more today I can say the whole car is smoother. Shifting is even smoother now because I am not having to give it as much gas as before. People might think I am crazy for this one, but my exhaust note even changed at higher rpms(6k+) not a lot but it did change, my non educated guess is that now that the coils are firing at full spark it is burning more fuel than before.

Interesting xexok..:)

I have posted this before, but keep in mind the 'B' iteration for the OEM RX-8 Coils came into production (line) install on Dec 1st 2007....so they were used on the very last of the Series 1 2008 MY, around 2 months of production use only, roughly 600 cars, as February and March were down months and few RX-8's made.

Then the B's were used on the Series 2's from April, 2008 production with the changed Ignition Coil Bracket, and upgraded Spark Plug Leads...# is S2 specific...

If I get around 70,000 KMS or 40,000 miles I think I would be relatively happy, certainly appears they are lasting longer than the Series 1 Coils ?.

At this mileage I would also make sure my MAF Sensor is cleaned, even look at changing Fuel Pump Filter/Sock or clean it, keep in mind the Sock is available as a replacement part, same as NC MX-5.# LFB6-13-ZE1 Sock Filter.

You shouldn't need to disconnect the battery to replace coils. Because this was done, the system is relearning and recalibrating the fuel trims. This will affect your ability to evaluate or compare the running quality immediately after the new coil installation.

I just don't like messing with anything electrical in the car without having the battery disconnected, its the smart thing to do. I have had my battery cable off many times before changing these coils and it never affected driving in any significant way like this did.

Good to know. My new coils are in the trunk - will be installing soon.

Umm, you should always disconnect the negative battery terminal when doing this. I took a look at the coil bracket and the difference appears to be for strength, not cooling IMO. And the white spots mean nothing, there was a TSB addressing that topic and it outlined the correct testing procedure. But honest every 30k is a good time to replace them, the wires, and the plugs.


If you have sub par coils you will definitely feel a difference when you install new ones. It's just that over time you lose performance slowly so sometimes you don't notice it.

I never do. I just make sure I have the ignition keys out of the lock.
I do it this way so our customers do not freak out while waiting for their trims to reset, thinking there are problems with our ignition system.

Well, you are a pro Ray! Unfortunately I have shorted something before (not installing my BHR coils :) ) by not following this recommendation.

There is no power going through the coil wiring/connectors when the key is off, so there is no reason to disconnect the battery and go through the fuel trim reset.

If you say so. I try and follow the FSM when I can.

Unless of course you are some form of perfectionist, and want to start out your new coils with a fresh slate when it comes to fuel trims.

Just because you don't need to do something doesn't mean that someone might not want to do that anyway.

More important to clear out the memory if the car was having drivability issues

BC.

In my case, I like to know the response to each individual component or adjustment. That's why I'm replacing plugs, coils, wires individually, so I can observe what affect (if any) each one has on the running quality. I can certainly do a fuel trim reset separate from each of those, and see what effect that has as well.

Yea that is what I figured about the power, but I am just guessing that its true. I know the chances were slim I could mess something up with the battery connected but something could still happen.


Please do make a thread once you start replacing stuff. My coils + wires were the biggest difference for me, when I changed my spark plugs I didn't really notice anything at all but that was on old coils.

Officially, MMC (FSM) recommends you disconnect the Negative Battery Terminal on just about every repair or parts renewal procedure that has a current (12V) going through it.

I guess in the end they are protecting their backside from any "litigation" in the event something goes wrong.