Robert Turnbull

Hi All :-)

I have a 2005 RX-8 Manual since a year.. Awesome car!

I live in Mauritius and RX-8 expertise is hard to find! (It is not an 'officially' imported car). I doubt anyone on this small island has the rotary compression tester, is it worth using a standard one?

Issue:

When starting the car from cold it either:
1) Starts on first turn all happy
2) Extremely hard to start (5-10s cranking) including one or more backfire gunshots - Scares neighbors! When this happens the revs climb slowly to 2.3k (2 seconds or so) when the car finally fires
3) I can easily bump start the car first turn @5Km/H on 2nd Gear

Car starts fine when hot :-)

It has a very slight rough idle when hot (Can drop to 815rpm and shake slightly when cold and moist outside)

I have followed the 'Symptoms' thread and 'My Car Wont Start' thread in attempts to find the answer.

Things I have got done so far:

1) New Battery - Existing one was on point of collapse anyways.
2) New Sparks - No Change
3) New K&N Filter - Hard to get the stock filter, so prefer a reusable one
4) New Thermostat - Preventive measure when I bought the car last year
5) Cleaned MAF

Things on the way:

1) New Coils - Want to finish the ignition triad - Shipping to MRU takes time!
2) Upgraded Starter 13 teeth/2kw - I still have the 1.3kw one

Is there something else that can cause such a 'can start fine / hard start' random issue just when cold?



EDIT:

Just wanted to add:

1) I get no engine code (according to cheap bluetooth OBD2 tool) nor any dash warnings, it just backfires on a hard start and makes a noise.
2) Alternator is working fine and battery reads 14.2V when idling.
3) OBD2 reading of temp shows ~90C sprinty driving and ~94C idling

wcs

iTrader: (2)

Ugh no Mazda rotary mechanics around ... that's rough

Ok ok this Youtube clip isn't bad on how to use a standard compression tester to test a rotary.

Robert Turnbull

Thanks for the video, I will show it to my garage when I bring the car for the coil change..

My coils have arrived in Mauritius and am waiting on customs clearance.

This was last night. I have decided not to touch the car until I get the new coils come in.

What IMO is the issue is that on the first few turns, its not igniting due to bad spark, and floods the engine making it harder to spark and have the gunshot backfire.

Am I going in the right direction for diagnosis?

elford_tim

It might not be flooding (they become almost impossible to start after they flood) but I think you might be on the right track with it igniting unburnt fuel after it finally fires. That's not going to do your cat any good...

I think new coils are a good step before digging in further, the coils really don't last that long, even though it will run on bad coils for quite a while - mine had bad coils on it with ~120k miles on them and it still started and ran, but the difference with new coils was massive.

Robert Turnbull

Hi All,

Here is an update to my problem. After installing my 4 new Ignition Coils, the car is running finer than ever


If you guys ever have similar symptoms, it will be good to look at the coils first!

BigCajun

iTrader: (1)

If you still have a catalytic converter, you need to inspect it.
Misfires kill cats, bad cats kill engines.