TynoPrime

Hi guys, so my problem is this : over the past couple of days I've noticed that once the engine has warmed up it feels more like a 60 who car rather than a 160whp one! When it's cold it pulled the whole way through the rev range. Once hot it pulls ok (not great) to about 6000 then pulls slowly after that. (2004 231 mt)

Please bear in mind I don't have ANY pending or permanent codes coming up. The Eco thinks everything is fine.

What could this be? Cat failure? Coils going? How can I tell if it's the cat?

On another note - I have an ignition spark tester - Ive read that it's best to test the coils under load so how do I stop the engine starting Jen testing them? Pull out the fuel pump fuse?

Also can I pull the spark plug and rest it on metal to test the whole system? (all the way down to the spark plug - not just the coil!)

Any help would be great. Thanks!

Gordon

wcs

iTrader: (2)

Well Gordon this is a very interesting and unique problem you are having ....

I'm going to go out on a limb and say low compression ... get a compression test performed from a Mazda Dealer or someone you know understands the rotary engine.

Yes it could be the CAT or the Coils or Plugs and Wires.
What's the mileage?
Have you ever changed the plugs or coils?
Yes you should check the CAT ... a very very common problem on 2004-2005 models.

I understand you are not a NEW owner or Potential owner ... but this thread has all the answers you want, read at least the first 9 posts.
https://www.rx8club.com/rx-8-discuss...t-here-202454/

RIWWP should really re-Title the thread to something a little more appropriate ...

Maybe this "All RX8 Owners past, present and future you must read this thread or your soul will burn ... mouhahahahahahah"

EDIT:
Oh and what do you mean test the spark under load? How much load?
At idle depending on what is turned on like the lights and the AC you're going to get in the neighbor hood of 20-30% calculated load on the engine.

TynoPrime

Thanks for the reply! I hope it's not compression - it has absolutely no problem starting when cold or hot - literally starts within a second hot or cold. It has 50,000 miles - last owner changed the coils back in April however after sneakily looking at his eBay purchases they were cheap Japanese ones, not official Mazda. He replaced these because he flooded the engine. I'm not sure if he did the plugs at the same time but I would have hoped he did!

Sorry, what I meant was I heard that reading omns is a poor way of testing the coils, and you instead use a spark tester and turn the engine over? Is that correct? Or so you physically unplug the lead from the plug (leaving the plug in) and run the engine, seeing if the cool is sending a spark?

Thanks

Gordon

musclecarconvrt

When my coils died the first time, about the exact same thing was happening until one day it just wouldn't start anymore. I rigged up a couple of grounded metal strips to clamp the plugs to, disconnected the fuel breaker, and turned the key to find one of the plugs not firing at all and another not firing very well. Replaced the coils and all was well. That was years ago at about 80k miles on an '04.

* edit * oh yeah, bad coils won't throw a code unless you lay on the gas while it's hesitating bad enough to throw a misfire code which is not coil specific.

Best of luck.

TeamRX8

iTrader: (25)

one of the first things you need to learn around here is that there is no shortage of people who will send you on a wild goose chase

https://www.rx8club.com/do-yourself-...-wires-222641/

TynoPrime

Haha, I did notice. That's the main reason I started my own thread. Searching just brought up "it can basically be ANYTHING" thanks, that's exactly what I was looking for - however do I run the engine with it disconnected then? Or do I do as musclecaecnvrt said and disconnect the fuel? Does running it for 15 seconds at a time 4 times over not cause a risk of flooding it?

Thanks a lot guys - really appreciate it.

wcs

iTrader: (2)

Mmmmm I forgot about Teams Coil Testing write up.

Sorry about that ...

I hope you find out it's only your coils.

Keep us posted

Mint87rx7

yes absolutely disable fuel or you will flood it, injecting fuel without spark....