Mx5 idle to high?

[Pokmx5]

Hey guys, just curious what everyone's mx5 idles at when hey have radio heater and lights on? Mines at 1050 1100... Is that normal?

[tescoking]

Hey guys, just curious what everyone's mx5 idles at when hey have radio heater and lights on? Mines at 1050 1100... Is that normal?

Depends on when did you start the car, if you start the first time of the day of cause it will has higher idles, the other reason is when you turn on the A/C. My NB idles stay at 1000 after warm up. It is normal. Unless your Idle air control is too old, otherwise it wouldn't be too high or too low under normal condition. Around 1000 is normal, give and take, every car have different condition and set up, it might effect the idles as well.

[hks_kansei]

There should be a sticker under the bonnet that tells you the idle speed.
I seem to recall 850rpm+-100, but I might be thinking of my other car.

Of course, that speed is with the car warm, and with no load.
Heater won't make a difference to idle speed, headlights and fan running may make it drop slightly.


When stone cold the car idles higher in order to warm up. (mine idles at about 1100 until the o2 sensor warms up, then it drops down to just under 1000)


edit: NA will idle higher for a little longer than the NB as the NA doesn't have a heated o2 sensor it relies on exhaust heat warming the sensor enough to accurately read mixtures.

The coolant temp sensor also plays a role in idle speed I think, I've just noticed on my car the o2 sensor seems to be the main factor in when the idle drops down (I have a gauge that lets me know when and what the o2 sensor is reading, $15 from Jaycar, great to let you know when it's open loop, closed loop, or over-run)