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Bad Misfire at 6,000rpm and low power when cruising

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Old 10-18-2009, 12:13 PM
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Bad Misfire at 6,000rpm and low power when cruising

Today I am experiencing what sounds like bad misfiring, (if it was a normal four cylinder engine it sounds like only two cyliners working) when I accelerate through 6,000rpm. This seams to be worse after cruising on the motorway for a while. Also while cruising on the motorway at around 4.5k it sounds like there are continual smaller misfires.

Whats more when I drive off from lights it's taking forever to get up to speed. (took about 10sec to get up to 30mph).

Foot down and hardly a thing happens.

Any thoughts?

From reviewing posts it sounds like it could be bad coils. What do you guys think?

Cheers
Old 10-18-2009, 01:27 PM
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Sounds like you coils are no good. Also how many miles are you your ignition coils and spark plugs? I would also check you cat converter to see if it red hot after your done driving. If so you cat is toast
Old 10-18-2009, 01:54 PM
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Check your wires they ccome off at the spark plug.
Old 10-18-2009, 03:01 PM
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Thanks for the feedback. Will check the leads and probably get some new coils, leads and plugs.

Any suggestions on leads or coils? Looking at some Magnecor 8mm leads
http://www.mazdarotaryparts.com/b-fe...etb-1373-p.asp

And the Mazda uprated coils
http://www.mazdarotaryparts.com/bfe-...ksb-1399-p.asp

Are there better ones out there?
Old 10-18-2009, 08:40 PM
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BHR coils, expensive but will last foeever.

PM Charles R Hill...... tell him Razz sent ya!
Old 10-19-2009, 07:45 AM
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Originally Posted by Razz1
BHR coils, expensive but will last foeever.

PM Charles R Hill...... tell him Razz sent ya!

Any idea if these are available in the UK? Or are they only in the USA? Any links on where to get them from?

Cheers
Old 10-19-2009, 07:59 AM
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go to this thread and send him a pm

https://www.rx8club.com/series-i-major-horsepower-upgrades-93/black-halo-racings-product-line-146611/

he is very helpful and honest guy. "best customer service"

he ships worldwide.
Old 10-24-2009, 08:56 PM
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Did you ever figure out what the problem was?
Old 10-28-2009, 08:25 AM
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Originally Posted by bhop
Did you ever figure out what the problem was?
Have ordered some uprated Mazda ones here in the UK. Let's hope that they will resolve the issue.

Does not happen all the time and the computer does not output any error codes. So fingers crossed.
Old 10-28-2009, 09:26 AM
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Definately coils. Same thing just happened to me. I would replace the coils, wires, and plugs. Thats what I did and the car runs great now. This is a very easy DIY. Look for "how to" posts on this site or on you tube. Should cost no more than $500.
Old 11-15-2009, 04:20 PM
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Missfire still there

Well I've now replaced the coils with uprated ones and the plugs with Denso IRL01 and IRT01. It was hoped that this would get rid of my chronic misfire from around 5000 revs up and appalling fuel economy. Well it has reduced it but not got rid of it. It's still pretty bad and pickup after a 1hr drive is crap. Also the fuel economy is rock bottom (about 5.5Km/Lt - Whatever that is in m/gl).

So now thinking I will change the ignition leads to Magnecor KV85 leads. Does anyone have any thoughts on these leads?

If anyone has any thoughts as to what else could be causing the chronic misfire (it only happens when the engine is hot and sounds as though it is crackling) any info would be appreciated.

In the mean time I'll get a new mortgage for the fuel and just have to settle with plodding along behind everyone else.

Cheers
Old 11-15-2009, 04:22 PM
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You have a bad Catalytic Converter!
Old 11-15-2009, 05:49 PM
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Originally Posted by Easy_E1
You have a bad Catalytic Converter!
yup, not sure why so many people thought it was coils. classic symptoms of a bad cat
Old 11-16-2009, 01:20 AM
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Originally Posted by Easy_E1
You have a bad Catalytic Converter!
Okm will look at that as well. Will try and get under it after a drive and see if it glows. At least it should be visaible what with it eing dark out now.

May rven contact Mazda and see if there is some kind of extended warrantee for the cat, since it has nly done 86k miles and is 4yrs old. Out of normal warantee I know.

Prob end up with a after market one.
Old 11-16-2009, 01:25 AM
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Drive it till it looses power then look at the exhaust up front, by the engine. About a 1/2 meter back from the front tire. Good luck with the dealer.
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