Curing a few possable Non Start problems with Spark plugs for your RX-8

[Mazdarotaryparts]

I decided to put this here rather than the ForSale section as this post is about information more than anything else and may help a lot of RX-8 owners long term.

As most of you know there has been a problem with RX-8\'s non starting at times due to flooding,this is a problem that has affected Rotary\'s for many years but it is a problem that can be cured by using a combination of Spark Plugs of different heat ranges.

Please read our Mazdarotaryclub FAQ on Spark Plugs for a full explanation of how and why plugs affect these cars.
http://www.mazdarotaryclub.com/forums/showthread.php?s=&threadid=264&highlight=bur9eq

As a distributor for NGK I have worked closely with NGK technical discussing this problem in depth for weeks because I had realised that RX-8\'s only come fitted with \'\'cold\'\' plugs, i.e. of the \'9\' heat range and this was the most probable cause for the non starts that have occurred, especially knowing that a lot of the time flooding occurs if the car is not warm up and is turned off very soon after staring when the vehicles cold start system is still in operation and leaves too much fuel in the combustion area and the colder plugs are unable to fire this \'\'wet\'\' mixture.

After much research with NGK they have now found a Spark Plug in the \'\'7\'\' heat range that can be fitted into the Leading Side of the engine ( standard \'\'9\'\'s  stay in the trailing side) , we are now in a position to supply these plugs to our customers safe in the knowledge that these have been tried and tested in many many Mazda\'s without any problems and are now available from ShyAuto.

This is written in the hope the above will help these cars not only now but also as they become older and  is in no way meant to be detrimental to Mazda as many many cars on the market have a small Achilles heal, but with this addition to your engine and information hopefully this problem will be severely alleviated, and enable RX-8 owners to enjoy their cars all the time, because they won\'t have to worry about a non starting situation occurring.

All the best Clive

[MikeLMR]

on a similar note, has anyone run the rx8 platinum type plugs in older N/A rotaries ? they are meant to last longer are they not ?

[Timrxmotors]

My rx8 has  \'8\'s in it,and they are Iridium,not platinum.Should last 36000 miles,til they need replacing.No starting problems since an ECU \'flash\' by Mazda.

[MikeLMR]

so is anyone using the new IRIDIUM plugs in an older rx then ?

[John Yorke]

I have run iridiums in mine for the last 2 years [currently 10.5\'s] still change them every 12k though

[MikeLMR]

were they Rx8 plugs then ? or does NGK make older style iridium plugs ?  I\'m tempted to order 4 RX8 plugs instead of the usual ones before I put the 7 back on the road next summer.

[John Yorke]

Originally posted by MikeLMR
were they Rx8 plugs then ? or does NGK make older style iridium plugs ?  I\'m tempted to order 4 RX8 plugs instead of the usual ones before I put the 7 back on the road next summer.

Not sure of the plugs Clive is selling, NGK / HKS retail Iridium plugs for RX7\'s you can get 9\'s, 10\'s, 10.5\'s and 11\'s.
Having not seen an RX8 plug do you know if there are any differences?

[clive]

As official NGK and Denso and SplitFire distributors we should be able to source Iridium plugs for older Rotarys with a little research to make sure we are supplying the correct plug.

Couple of things about what l have found out about Plugs lately.

RX-8 Plugs are two different lengths, (leading and trailing)and cost £38+vat from Mazda !! we will be able to supply plugs for these cars  for a lot less.

Denso make HKS and Blitz and just badge them accordingly, and my advise is now to people NEVER EVER fit these Iridium plugs in a Rotary as l have known two people loose tips and have engines destroyed because of the end falling off the plug!!

Denso were naturaly not willing to discuss this but NGK are awear of their problem and know what causes it,

Combustion Fequency shatters the Denso/HKS/Bitz plugs.

NGK have never had this problem.

[clive]

Originally posted by John Yorke
Not sure of the plugs Clive is selling, NGK / HKS retail Iridium plugs for RX7\'s you can get 9\'s, 10\'s, 10.5\'s and 11\'s.
Having not seen an RX8 plug do you know if there are any differences?

Hi John,

Referance my last post, if you have HKS fitted please throw them away while you still have an Engine.

[John Yorke]

Originally posted by clive
Hi John,

Referance my last post, if you have HKS fitted please throw them away while you still have an Engine.

Hi Clive
I ran HKS for best part of 12k miles without a problem, they were replaced with  NGK 10.5 iridiums leading and trailing, I was aware of the problem with the HKS, I think we did discuss this some time ago and they were replaced soon after!

[zevans]

Just two observations as another owner...

First, the plugs do seem to get fouled when queueing for extended periods (Trax was the first time I noticed it - took me over an hour to get from McDs to the stand at the show, and the car was NOT HAPPY.)

Originally I thought this was a heat soak problem, but I\'ve now noticed the effects last until you next get an opportunity for a thrash, even if that\'s a few cooling / heating cycles later. Therefore I think it\'s dirty plugs which stay dirty until you get a good opp to clean them through high-rev driving.

 (Sadly a lot of my miles are for 9am customer meetings, so I\'ve repeated this experiment far too many times.)

Second, the flooding issue was a biggy with early cars, less so with later ones, almost gone with the L flash, and totally gone with the M flash, so I really wouldn\'t change plugs just because of that. If you are having flooding issues and your car was from Q1 (or maybe early Q2) this year then ask the dealer to bring your PCM up to date. Basically, the revision changed shutdown and startup to make sure there\'s not too much fuel around as Shy describe.

Of course if you\'re sure you\'ve got this problem and you have the latest PCM, then kudos to Shy for providing an alternative which might just fix it!

[MikeLMR]

I also get plug problems if the car is stood for a long time at idle... happens every year I take the car to JAE ! it also hates beeing stood for a long time too as it takes a good long run to clear its throat again after being stood 2-3 months.

Can you get the iridium plugs for the 1st gen then Clive ? would they suit my car being that I use it so infrequently ?

[scooby_si]

i hear JAE is not at billing next year that may help.......
Si