05 GT 6speed
36k miles
MS CAI
New spark plugs
New Ignition Coils
Decarbed 3k miles ago

So, Ive had this wierd idle for aslong as i can remember. When at idle it tend to dip down to the point where the car starts to vibrate a bit more than usual and then it kicks back up. This also happens after a "spirited" drive and the rpms would drop even lower until it kicked back up. I've taken it to the dealer to get checked out but unfortunately could not reproduce the problem.

I recorded the problem on my phone and have linked the video at the bottom. (**** quality)

i have searched and found a bunch of threads where the idle has been cured by changing coils or spark plugs but that has not worked for me.

any help/advice is appreciated.

and yes im a noob.

Video: http://s663.photobucket.com/albums/u...t=VID00003.flv

 

mine does that too.. after i installed my AEM. it wasn't like that with my k&n

 

Check your MAF sersor it may just need to be cleaned

 

ive cleaned it once before and it didnt do anything but ill do it again just to make sure.

 

Your sp wires would be due to change.

 

yeah im gonna order some spark plug wires today and see if that does the trick. thanks.

anymore suggestions???? TIA

 

Yeah buy some new spark plugs and spark plug wires. Fluid Motorsports and BHR have some nice spark plug wire sets. Unless you want to stay OEM

 

That is pretty normal for a car with those miles . You will chase your tail trying to fix it .

Mine only came right after I had my engine rebuilt so it could be related to compression or carbon buildup .

 

Also with the weird idle may be a bad motor mount or mounts.

 

im gonna go with aftermarket wires. ill check out bhr and fluid for prices.

Brettus: when i took my car to get checked out i took it to kevin (Teknics) at wayne mazda. hes a tech there and he knows his stuff and said my engine was strong. and i decarbed my engine recently and i think kevin also decarbed it when i was there. but ill try to get a compression test before im out of warranty just incase.

 

I have a similar issue and the dealer told me it was missing but I guess he means miss fire. He said it needs new spark plugs and ignition coils. It is a 2005 Touring rx8 aero package. I had my motor mount changed but that did not fix it when it drops below 1000 rpm and rises back up on its own. He gave me the estimate and it was $855.00 to change so I'm gona buy a aftermarket ignition setup and have Altered atmosphere install it.

 

yeah i received my BHR plug wires yesterday and i plan on swapping them on later tonight.

hopefully that fixes my issue. if not then ill be sad cause ill know the issue is something more severe

 

so the ignition coils and plugs didnt solve my issue.

guess its time for a compression test.

 

You have to drive the car for a few cycles. Also did you re-set the ECU?

your link is not working so.... you could have a bad neutral switch. That causes a hunting idle.

HAve you cleaned the MAF?

 

well i disconnected the battery. do i have to do the other ecu reset procedures??? and the brake pedal one never works for me.

and ive driven about 100 miles since.

 

hmm im having the same problem too but mine rattles the plastic outside by the wipers and it gets noisy...I changed the plugs/coils and cleaned MAF but didn't work.

 

If the battery was disconnected for ten minutes.

Szymon take it to a loacal club meet.

 

hmm ill try resetting it after tomorrow and see what happens.

and in my the issue wasnt that noticeable. after "spirited" drives it does it more dramatically. the needle will drop to the normal idle and then immediately drop like 200 or more and then kick back up.

 

^that's what all rx8's do.

 

ive driven other 8's and observed their idle.

none of them feel the way mine does. all the 8's ive sat in feel like the engine isnt even running. but mines is a whole nother story. and this happens every now and then when im just idling in my driveway or parked.

 

mine does the same thing after it has warmed up and hot. it goes down to about 800rpm at idle for a second or so then jumps back to 1000. It cycles that way

 

Alot of this has to do with the pig rich fuel mixture from Mazda.

 

Add 6-8 ounces of MMO or any other prefered premix.

 

yeah thats what i also had in mind. ill try to pick up a cobb from MM and do some data logging etc.

 

i know nothing of premixing or said MMO lol. ill have to search later and read up on it. but from what little ive read there are some people who say their rough idle issues are fixed by premixing. but like i said i have to read into it.

but im still leaning towards mazdas ridiculous richness lol