Hello,

I've got a 2007 RX-8 with just over 77k miles on it. Its the base sports model, with the performance package (larger wheels, bigger brakes). Its the sports-AT with the manual shift option. I've had no problems with it until recently when the CIL popped up in the driveway, it started idling rough and when I threw it in reverse it would stall.

I bought new ignition coils, plugs and high tension wires. I also bought the replacement ignition coil plate with the holes behind the coils. When I was replacing them, I discovered the dealership had significantly over-torqued the spark plugs, took some effort to get them out. They also didn't install the wires properly on the leading spark plugs as one had rusted, and the other had rusted and sheered off (see photos).





RX-8 plugs the lower (leading ones) were completely rusted - thank you Mazda dealership for not putting the boots on right!

The RX-8 hadn't ran for about two months, the last time I ran it, it basically idled very badly for about 2 minutes and then stalled. Today, after I installed the new parts. I had recharged the battery (was measuring about 12.2v). When I started it back up, it started up on the second go and idled normally for about 30 - 45 seconds. It started to drop RPM, so I slowly revved it up, where it was fine. As soon as I took my foot off the accelerator, it sounded "distant", and the RPM dropped from idle and it stalled out.

I left it for about 2-3 minutes and tried to restart it. It would crank but wouldn't start. I thought since it only had below a 1/4 tank of gas in it, and that its sat there for awhile, plus it hand stalled out without warming up the last time I ran it, that maybe it was flooded. So I followed the procedure in the owners manual. I've only ever stalled it one other time, and the procedure in the owners manual got it going again. This time though it won't start.

I took the front wheel off and rechecked the spark plug connections, they all seem to be fine. The last couple of attempts to start it, the dash did some weird stuff, the RPM gauge would jump from 0 to max RPM and back down again, and the lights would light up and dim. It sort of looked like it was "rebooting".

I've stuck the battery on the charger overnight, since its running around 11.0 - 12.2V according to the charger. The battery is one of those Autocraft Gold things from Advanced Auto Parts, its about 3 years old. I'll go get it checked out tomorrow.

I was wondering if anyone had seen this before? I was wondering if any damage could have been done to the engine with the damaged plugs as I've no idea how long they've been rusted like that, but the inside of the boot on the one that was sheered off looked like it had been firing inside the boot for quite awhile. I had no CIL until it finally failed, so I'm guessing it stopped making contact.





Old spark plugs





Old spark plugs





Old spark plugs

Thanks

 

So do you have new plugs now? Battery is good to go?

I would start by getting fresh 91 or higher gas in there. May want to check your fuel pump and filter, too.

 

Yes, I've got new plugs, new coils and new wires. The battery is currently sitting on the charger. I'll give it a go in the morning, and if it doesn't start, I was going to take the battery over to be tested.

Its got about 3 month old 93 gas in there, should I siphon out whats in the tank or just dump fresh gas on top of it?

 

If the fuel is bad, you'll want to get rid of it. Though adding fresh to your current tank may not be bad.

The check engine light needs to be read and posted, as well. I should have mentioned that before, but I'm hung over...

Clean your maf and eccentric shaft position sensors (followed by the 20 brake stomp procedure) and see if that helps with your idle. How old is your air filter element?

 

Classic example of electrical issues. Check your battery terminals! Are they tight? Are they clean and free of corrosion? How do the wires look? If that's not it, probably a weak or bad battery.

As far as the spark plugs go, MAKE SURE you use dielectric grease on the boots and plugs, this will keep out moisture and prevent future rusting.

 

Thanks for the replies! The battery terminals are tight but there is some corrosion on them, so I cleaned that off. The wires look ok. I had the battery on the charger overnight and that seemed to fix the weird dash issues, but it still doesn't start. I took some video of it this morning, the first one is outside the car, and the second one is inside of the dash. I've put the battery back on the charger and I'll remove the front wheel again this morning and try reseating the spark plug wires just in case...

https://goo.gl/photos/XomDA6i326vdXpdr8

https://goo.gl/photos/MYw8yzKVkXRN9DS1A

 

oh and the mobil1 in the background is for my wife's SUV, the RX-8 has only had castrol gtx (regular oil) put in it!

 

Does the starter turn at the usual speed? If your battery lost a cell you might not be turning fsst enough to start, especially on bad gas and possible flood condition.

Other thing: are all the intake connections that you took apart to get at the coils snug and nit leaking air?

 

The starter does sound a bit sluggish, if you check the first link that I posted above you can hear it for yourself. I'm going to run the battery over to Autozone to be tested here in a bit...

Yes all the intake connections are snug and are in good condition, so I don't think they are leaking air. I will double check though...

 

Yeah it does sound sluggish. Get that battery checked and see if you can pull and dry the spark plugs.

 

Alright, so I took the battery over to Advanced Auto, it was registering about 12v but was only kicking out about 410 Cold Crank Amps instead of the 620. Since its a few years old, I went ahead and got a new battery. Still doesn't start, so I will jack it back up and pull/dry the plugs in the morning...

Here is how it currently sounds with the new battery:

https://goo.gl/photos/FK6LNzdFCBUFJNs49