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The Idle dip is driving me insane!!!

Changed the spark plugs, cleaned the MAF, throttle body...
and the spark plug leads been upgraded to magnecor 8mm

read on miata.net that it could be the o2 sensor which can cause the idle dip.... Has anyone replace one yet? An which o2 sensor is it?


But I might also check the vaccum lines tonight...... and see how it goes

Prolly is the idle stepper mechanism.

Not sure if it's the same on NB, but on NZ there is this gizmo bolted to the undeneath of the throttle body (there's a pipe going to it from the plastic crossover intake pipe).

It's a valve that regulates the idle, and it goes on the fritz after a 10yrs or so. Only 100% solution is to replce it.

Babalouie wrote:Prolly is the idle stepper mechanism.

Not sure if it's the same on NB, but on NZ there is this gizmo bolted to the undeneath of the throttle body (there's a pipe going to it from the plastic crossover intake pipe).

It's a valve that regulates the idle, and it goes on the fritz after a 10yrs or so. Only 100% solution is to replce it.

hmm, is that on your NA8? could be the same for my NB8A

Did it idle dip with the before K&N set up?

YUP, happened with the no drill mania intake as well

so it's just dipping when you come to a stop?
mine's been doing it for a while now, just going down to 500rpm then coming back up again
I'm going to get mania to take a look at mine in a few weeks when I have the next service done

SM wrote:so it's just dipping when you come to a stop?
mine's been doing it for a while now, just going down to 500rpm then coming back up again
I'm going to get mania to take a look at mine in a few weeks when I have the next service done

yup same thing is happening to mine

Ok, this is gonna be from left-field but I had this problem on my Ford Festiva after I changed the intake significantly.
Before you all go Pffft! Let me remind you the Festiva actually has a Mazda engine designated B5.

I am obviously not the most knowledgeable, but maybe try to look for a little screw, close by the throttle body, that looks like it doesn't secure anything.

If the BP has the same fundamentals as the B5 then this screw will change the idle stepper-motor, increasing or decreasing the idle RPMs when the throttle butterfly is closed.
My $0.02

EGG80X wrote:YUP, happened with the no drill mania intake as well

If its not hapenning with the OEM air box but is happening with the aftermarket CAI, sounds like a MAF sensor issue.

well I still have everything stock in my car and I still have this problem

PS. Just did some seartching, so EGG8OX it seems you have had this problem before, seems it's common with NB8A's and 10AE's
some people who have said it's happened to their cars, Blugg, Insurgence, fig, Fra66L, and more

This happened to my NA6 and after following these instructions all fixed

http://www.miata.net/garage/KnowYourCar/S7_Idle.html

not sure if this applies to NBs though

Richard

Interesting. Might be worth checking that one on mine too. Mine idle dips only when the engine is cold, and that's it. Never does it once it's warmed up.

Have you set the base idle speed correctly eggbox?

its call a throttle dampening valve =)

http://www.miatamania.com/Shop/ViewProd ... ortOrder=1

Richee wrote:This happened to my NA6 and after following these instructions all fixed

http://www.miata.net/garage/KnowYourCar/S7_Idle.html

not sure if this applies to NBs though

Richard

Garry wrote:Have you set the base idle speed correctly eggbox?

yes it works fine now thanks!!!!