Rx8 bad idle and misfires
 

Details: 04 manual trans. 60k miles. got new plugs about 3-4k miles ago.

this pretty much the same as whats happening to mine specifically the weird behavior when idling:

So I just got my rx8 back from an inspection (NOT a rotary specialist but does normally deal with many exotics) and it passed. He replaced the air filter and changed the oil.

My brother took it out one morning... so i'll just relay what he said. He may have not warmed it up fully he said he let it idle for at least 2 min before taking off though. When he got on a main road and started to accelerate then engine started hesitating, he said it sounded clogged. There was loss of power. He then took it back home.

When I started it up a few days later:
I started it, started fine. As soon as the idle got down to normal range, it began sounding like it was about to stall out, then engine slowed down dramatically, then it would bounce back up to about 2k-2.5k RPM. Over and over again. Also at this time I got a flashing CEL (misfire). It would go to the edge of stalling, then bounce back up. It would slowly come back down like it normally does during start up. But it sounded very rough and clogged.

Any idea whats going on with it?
Thanks any more details need please let me know.

Sorry after posting it looks like this would be better suited in series 1 tech garage? If mod could please move it thank you

This thread is a good place to start.

https://www.rx8club.com/series-i-tec...t-here-222280/

Coils..upgrade em.. pays off..

The gm coil upgrade is well worth the money

bad coils can cause misfires at idle? god i hope so.

What are the chances its low compression? I've never been unable to start it hot. My starter is on its last legs too.. Thatd be very devastating.. I always warm it up and red line it when ever possible.. constantly topping off oil etc.

OEM quality coils need to be changed roughly every 20-25K miles. They are considered a wearable item in this car. Letting them go bad causes all sorts of problems--some of them very bad.

Start with the ignition and see what that buys you before worrying about catastrophic failure. Change the coils and wires at the same time to remove all doubt. (I see you recently changed the plugs). Pull the plugs and inspect them. Replace them again if they look bad. Post pictures of them here if you like. The condition of the plugs can tell you a lot about what is happening.

Clean your MAF and ESS. Taking care of those two items is virtually free.

Go down the list in the thread I linked in methodical fashion. It is filled with correct information presented in stepwise format.

It was the coils good call. Runs like brand new now. Thanks :)

glad u were able to get her back to 100%

Will happen again .. put some ls2 ones on it ;)

Thanks yea whenever I run into something like this I always think its bad compression and start panicking. Then once I fix it I feel like my engine can go another 100k lol

But yea its amazing what new coils can do I'm still on original starter and it always took 3-4 sec minimum to start and now it starts instantly. Same OEM starter from 04.