Really sorry if this is a recurrent problem that is labelled otherwise, but I was wondering if anybody else was coming across this problem (if it is a problem).

Is my engine supposed to "auto-rev"? It happened this morning, but it has happened before. I think it's okay since my engine seems to be falling sub-1k RPMs and its trying to save itself, but should that even be happening when the engine is warmed up? I'm a little bit concerned since I've hit my 30k mile point, and I know I shouldn't be worried since I've never flooded my engine, but the worry is still there.

Can anybody clarify to me what's going on?

 

if you start cold, the ecu will make it idle at about 2k

 

I think I know what he is talking about.

It happened to me too.

 

It has only happened to me on really cold days, but yes it can happen.

 

cars will limit power when the temp is cold outside and the motor is cold..


my celica used to do this all the time.. i wouldnt go into lift, until the motor was warm..

probably its a good idea to let the car warm up to temp before really getting onto the throttle.

but after the car is warm your rev-limiter issues should go away.

 

How high is it revving up too and how long does it stay there? I idle higher at startup on cold days, around 2-2.5K but with it being warm/hot it usually doesn't go over 1500

 

Hunting usually is the result of a vacuum leak or throttle body icing.

 

oh so it's idling... that makes more sense...

but it's not even that cold... 60 deg outside?

what's "hunting"?

 

The car's possessed...

Now, did it "auto-rev" while you were driving or when you first started up cold in the morning?

Mine revs up to about 2.3k RPM when I start it up cold.

Sometimes in very extreme cold climate, it'll "auto-rev" when you're in neutral when the car's been on for a bit. (Somewhere around <35 degrees Fahrenheit)

 

well i'm mainly worried cuz it's revving like that when the engine is already hot after about 10 minutes of driving... and it's, well i live around the OC so it's not cold at all right now... it'll probably be better later on

 

Was your AC on? Sometimes the AC causes the RPM to drop when it kicks in and then it'll jump to like 1 to 1.5k after it turns off.

 

O.o it was! haha next time i'll try and see if that was the issue...

 

so wut does neutral switch failing do?

i drove my car a few moments ago (7 pm), and it's still doing the same thing. It revs up to about 1.5k then goes back down... then back up and back down in a constant cycle. It's about 75 outside, and my CEL just came on...

the only thing i can think of that may have affected my car is that I just went in for a 30,000 check up at a rotary shop (well they work on rx-7s, but they should be able to be fine with rx-8s rite??) and they put in 5w-30 Castrol GTX (that shouldn't do anything right? and of course these fires putting out ash all over socal... but since noone else is getting this problem, it's probably something else. at this point i'm because i feel like i should have just spent the $350 to get the Mazda dealership to do a 30k check up.

 

oh and will an exhaust nullify any warranty work?

 

yep,

it hunts back and forth between 1750 and 900..

beers

 

read the owners manual. see what needs to be done at the 30k check.. knowledge is power.

then address the issue.. i will give a cel for the neu switch, but it takes a long while..


beers

 

or vaccum leak.

With that many miles................ did you get new plugs yet?

Get new plugs first then see if it's ok.

Is it dying and too rich from the smoke form the fires? Ha ha... just kidding!

 

^^ yea, i just checked the owner's manual and checked it with what the service guy did, and he did everything he was supposed to and even replaced the spark plugs with new oem mazda ones (problem occurred after this).

my engine has hunted in that range before, but it wasn't consistent. hopefully, whatever the problem is will be the less costly to fix...

i'm getting it checked out at mazda next week, and i'll post what they tell me (just in case other people run into the same problem as me).

^ knock on wood on that one...

 

I dropped my car off last week for this same problem. They said they reset the base idle and it was fixed after being there for about six days. Then later than evening after driving about 40 miles it was doing it again. Now its back at mazda today for a CEL that came on last night. They said that they cant get help with the revs because the mazda tech line they call is in South Cali and the fires are around that area so no ones there. Let me know if you find out before me. Ill post when I know something.

 

Got my car back today and they told me it was my park/neutral switch so tell mazda to check that out!

 

will do... i'm getting it checked out tomorrow <crosses fingers>

 

yea, they said my neutral wiring got completely pulled out, which may have happened either when i took it in to get my trannie replaced or maybe when the mechanic did something around there... where is the neutral wiring anyways? i hope id idn't pull it out when i installed my AFE SS...

 

the neutral switch is somewhere on the side of the transmission.

You can look at it on the passenger side. or the other side, I forgot.

 

My car just started doing this a few weeks ago. 30K 2004 manual.

No vacuum leaks, no codes (checked with a scan tool).

Usually happens when engine is cold (still warm here in Phx.), but will do it sometimes when the engine is warm. Idle will roll/hunt from ~1400-1900 RPM, but if I push the clutch pedal in the rolling/hunting immediately stops (normal idle), then as soon as I let off the clutch pedal it starts rolling again.

So, is it the Neutral switch or the Clutch Pedal Position sensor? I know the CPP is on the driver side of the tranny, not sure about the Neutral sw.

Anyone get a definitive answer? If it is the Neutral switch were it it located?

 

If it's the neutral switch, is this covered under warranty or is it a "wear" part? Mine started doing the same thing a few weeks back, but hasn't happened since.