I have been having a problem for some time when the car is idleing. I did a search and read several threads with people with the same issue, but no one who posted a reply saying their issue was resolved.

Basically it stays around the 900 mark, and about every 10 seconds it drops down to around 700, and it feels like it may stall, and than jumps back up. It has been doing this for a few months now. It does this in park, neutral and in gear. I also tried it with the ac on/off and doesn't seem to matter.

It seems like it has gotten worse since I installed the MS CAI about 3 weeks ago. At the same time they installed that they cleaned the MAF, replaced the plugs, and cleaned the throttle bottle and injectors. After having this done I have seen an improvement in performance, most likely from the plugs and cleaning the fuel system.

I asked them this morning about replacing the coils, and they said it would not make a difference because the car is not mis-firing. Coils & plug wires are stock and have not been replaced. I was hoping to order the BHR kit, but just dumped a bunch of money into the wife's truck, so will have to either wait for that, or get the factory ones, and upgrade later. There are no CEL's either.

The car is an 05 auto, all the maintenance has been done by the dealer since I have owned it. It had 12K miles when I bought it and had all the previous service records. All the TSB's have been done regarding the computer as well. Other than the MS CAI car is still completly stock.

Any help would be appreciated.

 

Try replacing coils. Works 9/10 times. Do you have the screens in the intake?

 

he wouldn't know if the screens are in there or not. but the problem was going on before anyway.

i'm not sure, but you might try just resetting your ecu with the 20 brake presses method. then be gentle to it for a week and see if the computer responds in a positive way.

 

Thanks for the fast replies.

I'll try to reset the ECU, but the not driving it hard for a week might be tough.

I'll send a PM to technics and see what develops with that.

The tech did say he put the screens in. I wouldn't know how to check that though.

Any way to test the coils & wires?

I may have them check and see if the AC may be causing the issue. I have to have a lot of warranty work this Friday and the car will be there all day, and they said if they have time they would look into this problem further.

Edit: The car still has the stock wires/coils, and has 55K miles on it if that matters.

 

Hunting idle could be the neutral switch.

Search on that there is a video

 

The coils and wires have never been replaced, so they have 55K miles on them.

I saw some posts about the neutral switch, but does an AT have one?

 

I was wondering about that too ..... only MTs have it.

 

Curious, my car is doing this same thing.

I've been thinking it is a vacuum leak but I have not investigated it yet.

 

same problem. Does it matter if you have screens in the intake? I have an AEM cold air. Didn't put the screens though.

 

I'm thinking it is the AC compressor cycling also. The AC will be active all the time except when the AC is off and the selector is set to dash vents only.

 

oldie but a goody..

https://www.rx8club.com/showpost.php...54&postcount=8

note the if you disconnect the battery part for the 04, and this is for the 04 only.

beers

 

Same problem here... The dealer told me that its just the nature of the beast...

 

Well today I did the reset, both the one with the ignition/odometer, and the brake pedal. Only drove a little today, but did not once have a problem with the idle. Also the car is idleing a lot higher than before, around 900RPM's versus around 750RPM's. We will see how it goes after putting some miles on. Will also be curious how my MPG will be with the higher idle, I was getting pretty descent mileage, around 21-22MPG per tank with a mix of city/highway.

 

Well after a full day of driving the symptons are back, and the car is still idleing higher than it was before. It was fine this morning heading into work. Than around lunch time I went to make some service calls, and started happening within a few minutes of driving. So now it idles around 900 to 1000RPM, and is dropping to almost 750-800RPM. Does this almost consistantly every 10 seconds or so. Before I think it was actually idleing around 800 RPM's, just hard to tell with the tach. I just noticed that the needle is closer to the 1K mark now.

 

Are you serious? I just took out the screens of the intake (and cleaned all the damn oil in there) and resetted the ECU... and drove it hard the next day. When I resetted it, the whole car was smoother, my idle was better, no REAL vibration and overall, the car just felt different, but in a good way.

End OF Thread Jack?

 

I'm actually getting better mileage for some reason also... mine jumped from 22mpg to 25mpg and I drove harder too. Don't know what this car does sometimes, it really is Unique.

 

When I 1st got the car I was getting around 24-27 MPG. After I took it in for the M flash it dropped a lot. I drive the same route 5 days a week, give or take a little extra city miles here and there.
Thats why when I 1st got it, and read all the posts about crappy MPG I was thinking, really?? Still cant complain I guess. If I drive it like an old lady I can still get 23 MPG, but before I was able to drive it like I normally drive and got 24+.

 

I was wondering why mine still worked correctly after the battery was disconnected for days.

"NOTE: Vehicles produced before 9/11/2003 are not programmable N should have the AC amp replaced per Service Bulletin # 07-002/04 1."

It has the new AC amp due to production before 9/11/2003.