Couple minor issues to sort out
 

Hey guys, i've got a 2007 6MT with 82k on the chassis and approx. 4k miles on a Mazda Reman I broke the engine in using Racing Beat's recommendations and have since been driving it normally.

The engine is amazing, pulls really hard and power delivery is so smooth at full throttle the car feels slow as there are no dips or peaks in the power that can be felt.

BHR coils and plugs were installed about 20k ago, I re-used the plugs in the new engine but cleaned them, it also has header back catless exhaust and an AEM intake also using a cobb AP with a custom map from MM.

First off, about 80% of the time both when cold and hot the engine starts damn near instantly but in that 20% of the time it doesn't the engine just cranks for several seconds almost as if you left a plug unscrewed or had the fuel pump disconnected. It happens at random both when cold or hot. It will crank for like 3-4 seconds very rapidly and then just fire up as if you tried to start it with no fuel pump and then plugged in the fuel pump after 3 or 4 seconds of cranking. Any ideas?

2nd, the engine seems to randomly missfire at idle, it isnt large enough to throw a code or make the CEL blink, and it only happens one time on the Tach it looks to drop almost 100 rpm from that standard idle and you can feel it in the car. other than that it has a silky smooth idle.

3rd, my heater temperature knob is skewed, It will blow the full range of temperature of hot-medium-cold but hot is literally 3/4 of the motion of the knob medium is about 2 segments from full cold and cold only happens when positioned at full cold, any way to fix this?

That should be everything, any tips tricks or ideas would be much appreciated.

As far as your temp knob look at diy and you will find an answer. It is a well known and discussed issue. As far as your starting issue, it is normal. This happens in all cars. Every now and then all cars have a slow start. As far as your misfires, does this happen when the car is cold trying to warm up? I think all rx8s cough a little bit while warming up. However, I suggest you change your plugs and not just clean them.