My 2.3 3 (with only 6 k miles on it) started to experience a bit of a miss at Idle. Only when cold and only after running for about 2 or 3 minutes. Dealer went over it and simi-fixed it but seems to have returned. After it is somewhat warmed up it is fine.

 

try run engine using different air filter or with no filter for a little bit or maybe there is something wrong with spark plugs?

 

I'm having the same issues also.

 

About how many miles on your car? ------ 2.3 engine?

 

I will try to search on a tsb for this, let me see what I can dig up.

 

Here ya go everyone, there is a TSB, only for CA spec though. Not sure if it applies or not, a simple reflash of the ECM fixes it. Here's the TSB number and a quick explanation of it.

TSB: 01-031/06
2006 MAZDA3 WITH 2.0L/2.3L (CA SPEC ONLY) - ENGINE HAS ROUGH IDLE AFTER COLD START
APPLICABLE MODEL(S)/VINS

2006 Mazda3 vehicles with 2.0L/2.3L (CA Spec)
DESCRIPTION

Some vehicles may exhibit a rough idle for 5-10 seconds after a cold start. It may happen after filling up with 87 octane gasoline and then parking overnight. There is no DTC stored in PCM memory and fuel holding pressure is 36.2 psi or more. This is due to a sensitive PCM calibration to specific local gasoline quality.

 

The above is interesting but mine is not a CA car. Also mine only has this miss (not really a rough idle) after it has been running for about 1-2 minutes. Strange

 

It's worth a try. It may indirectly fix it.

It sort of "resets" the PCM when you re-flash it with a newer calibration. So then, it has to "re-learn" everything.

 

Have had my 3 with 2.3 engine to two differnent Mazda dealers. Neither can fix the miss or know what is causing it. i called the tech hot line and they do not know either. Hmmmmm?

 

My 08 MZ3 does the same thing for the first 2 minutes but goes away after warming up. My 07 Subaru does the same thing too when cold. I thing its normal.

 

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tundra, Interesting but wonder why neither dealer or even the Tech rep would say it is normal for this engine? Oh well, I will keep you posted.