Tony_22

Hi

I have a 2005 Rx8 automatic shinka and I've been dailying it for the past few months. I would regularly change the oil every 3 months and the only real big changes I did to it was changing some ignition coils and spark plugs.

Recently it wouldn't start after driving it for quite awhile and I would have to wait from 10-15 minutes before it would start again. The motor was rebuilt around 3 years ago and seems to run strong when I give it a fresh start, but after a few trips, it wont start again for awhile. I figured it'd be the catalyst converter but that wasn't the issue and my dad suspects it might be something electrical wrong but I don't know.

If anyone can give some advice as to whats wrong that'd be real helpful!

Thanks

NotAPreppie

Failure to start when warm is a classic symptom of low compression. Get a rotary-specific compression test before going any further.

If that comes back okay, get a fuel pressure gauge and check your fuel pressure. It's possible the fuel pump is starting to fail and not providing enough fuel when it warms up.

CaymanRotary

Compression test with crossed fingers. Not being able to start while hot is a very scary problem in this car. Good luck!

Tony_22

Damn I really hope it isn't low compression. I am gonna check that soon but how woild I go by doing it? Should I go to a Mazda dealership or just do It myself ? And Do I need a specific compression tester?

CaymanRotary

3 options really

1. You can purchase the tester online for $300 and do it yourself.

https://rotarycompressiontester.com/

2. Go to Mazda and have them test it with their rotary tester. Typically they charge out around $150.

3. Can use a regular compression tester but you need to measure both with and without the Schrader valve. Driven by Madness did a good video explaining how to do it. It's far more complicated but definitely cheaper. Wont be as accurate but will get pretty close.

NotAPreppie

IMO, do it right or not at all.
Stick with options 1 and 2. 3 will only get you close if you know what you're doing and, lets face it, most of us don't.

CaymanRotary

Yea, I just happen to live in a place with no Mazda dealer and none of the mechanics had the tester. I just bought mine about 7 months ago. Best $300 I ever spent. Not only good for my cars but also good if I’m looking at another 8 to buy.

furansu

Tony, where are you located?

If you plan to remain a rotary owner for a long time, and are the type to do your own maintenance, a rotary compression tester is a sound investment.