My 8 is a bit slow to start when cold.
In the morning or after work it takes several seconds cranking before it starts. Sometimes it doesn't start fully but just fires a few times before it starts.

No real problems when it is hot.

It has a recent very complete service from a local independent garage specializing in performance cars. They checked over the ignition system so I'm pretty happy that's OK.


The car always starts on the first go, I just expect it would start a bit faster...... Or am I just too new to rotaries still?

 

Well, I'd take a slow cold start over slow hot start any day for a rotary motor!

How long does it crank before it catches?
How's the battery health?
Also, I think the first few batches of RX-8's shipped with underpowered starters.

 

It's a 2005 so it could have a weak starter.

It can take 4-5 sec. Doesn't sound much but it feels like a pretty long time.

 

upload a video onto youtube of your startup, might help with diagnosing the issue

 

Check this thread. Post #3 has a TSB attachment.
https://www.rx8club.com/series-i-tec...recall-196072/

See if your car is applicable.

If your battery is healthy, it does feel like you need a starter replacement, or you can just roll with it. The only issue is that you may have significant trouble starting your car in colder temps.

 

Ok. YouTube videos!
First one for reference. Normal start

This evening. Took a bit longer

 

I would check starter (especially since your rx8 is a 2005 model), battery, and battery terminals (make sure they look clean and they are tight).

This tells us nothing...Not every shop out there understands rotaries. Our engine is very different than other performance cars. Having said that, how familiar the shop is with rotaries? How did they check your ignition? Did they test coils or just looked at them? How many miles do your ignition components have? Generally, ignition components (mainly OEM plugs and coils) should be changed every 20,000 to 30,000 miles.

 

Check your battery

 

Battery sounds weak to me.