In an attempt to chase down an intermittent misfire, lets play Good Coil Pack, Bad Coil Pack:





Let me know what you think of Left v's Right and if you think it is conclusive!

Cheers,
Hymee.

 

both of them are bad !

 

How can anyone tell the difference? One has a spot and the other one doesn't.

 

even new out of the box from mazda, the bottom can have watermark/fingerprint looking stuff on them.

 

the white spot on the bottom does not necessarily mean it's gone bad. Did you test them with a meter?

 

the bad one is probably the one without the white spot.
I would just put the ls2/yukons on!
OD

 

We've been playing that game for 5 years now. Troll! lol

 

All of the solutions I'm aware of are shipping.

 

is there a hump/lump/bulge in the case bottom of the top left one? hard to tell but if so that one is bad.

 

Yeah, the top of the coil (the ignitor part) is the only part of the coil that will visually show a failure, but its usually a catastrophic failure, not an intermittent misfire.

 

I was wondering if the "white spot" on the rear was a sign of overheating or something and that they were on the way out. The 4 of them from my motor have the white spot. The one to the the right of the photo is one from my engine.

One other possibility is that it is misfiring due to being too rich. That wouldn't be the tuneup, as it is essentially the same tune-up I have been running for ages, and all my boosted pro-tuner customers are using the same base. If the tuneup was wrong, then surely it would misbehave every time I hit the "wrong" load points. I can drive for 300km and not have a problem, then it can came back again. It can be really bad, but then come good again. It always seems to be in the 3000-4000 RPM range when a bit of load is added, but you can drive through it (i.e past 4000 RPM or so) and it comes good again.

So if the tuneup isn't the problem per-se, and it is misfiring because it is too rich, then the only thing I can think of making it too rich is an injector/s sticking open. Has anyone had that?

The problem is the same whether I'm boosted or NA.

I might look at the LS1/2 coils, since they are plentiful here. I just got to find out more about the connectors/wiring harness.

Anyway - more fun... just to keep me from being bored LOL.

Cheers,
Hymee.

 

Hymee: play process of elimination and just test each coil. If it were your tuning, I think you'd hear complaints from others using your software but since you haven't, I think you need to look elsewhere to identify what's causing the misfire.

If you've got a multimeter sitting around: http://www.finishlineperformance.com...16-07-1793.pdf

 

OK - I can't remember everything What is the test? Was it an ohms test?

Cheers,
Hymee.

 

LOL - funny timing our last 2 posts!

Thanks for that. I thought I had seem a bulletin like that some place. I thought I would have enough brownie points to get away with asking!

I'll check it out some more.

Cheers,
Hymee.

 

no problem Mark, hope you find the culprit.

 

The only thing "hard" about it is I don't want to have to drive 300km for it to present itself again - it is the intermittent thing giving me the *****.

Cheers,
Hymee.

 

Oh. I thought this was a theoretical test (chumming the waters for trolls, as it were).
I didn't realize you needed a real test.

The ONLY test that is conclusive is the timing light.
The coilpack resistance test will only show a coil on its death bed, not one with an intermittent misfire.

 

Ahh. Interesting.

I had almost this exact problem a few weeks ago (but in the 4800 RPM range) and replacing the plugs fixed it.
It would "hold back" rather violently and then "clear up" as soon as I got out of that range.

 

Thanks. When I was asking Grandad for his advice, he said "What are you ringing me for if you haven't looked at the plugs!!" LOL. Sounds nasty, but it was funny. You tend to have respect for someone who has run 6's with rotors. There ain't many of them out there. In fact, I know of only 3 or 4 - but hey, I might have blinkers on.

The other thing about mine is that when this situation is "active", it often stalls at idle. When inactive, it is sweet.

I enquired about plugs yesterday. Parts manager dude advices $430 bucks a set. FFS! He reckoned Warren should be able to look after it. Warren T.

I've just moved my coil packs back to their "normal" location. I moved them close to the ABS to help fit the blower in. I was wondering if the leads were arcing or something, but I would need to be looking under the hood while it was happening to be sure. Just got it back together, and about to go for a looong test drive once I put the wheel back on.

Timing light sounds like a good idea, but it only going to tell me that it mis-fired. I already know that.

All I know it is either fuel or spark. There isn't much else that it can be in gasoline engines At least the air is free!!

Cheers,
Hymee.

 

It is the easiest and most direct diagnostic we have on a motor. Sage advice!

Just use RX-7 plugs. Cheap.


But it will show which coil and when. Just tape it to the windscreen and go for a ride.

The devil is in the details!

Except in California.

 

Well, I just took her for a drive up to Steve Irwin's and back. (Fair Dinkum!) No crocs reared their ugly heads. I really need to drive it for a week and see what comes of it. If it lasts a week or so, I'll try to shorten my coil pack extension bracket and see if I can insulate between the leads/coils and the ABS bracket.

Lots of fun.

Last time I used the term "cheap" (or what it dear?) on a US forum, I confused people! But I hear you. I'll try Supercheap then

Cheers,
Hymee.

 

I think you meant http://www.supercheapauto.com.au/

 

you can always narrow the gap on the plugs a little--down to 30--see if that helps.
double check your wires--just a little jiggle in them can cause misfires---ask me how I know.
OD

 

Thanks for that. It was a funny mistake. I didn't think you'd even follow the link!!

Cheers,
Hymee.

 

OK. So it seems the white spot isn't an indicator, even thought one of my local Mazda parts guys said to check for it...

Still there sometimes. Is it misfiring cause she goes too rich? Sticking injector? The quest continues...

Cheers,
Hymee.