coil packs??

irwin83r · Postby **irwin83r** » Fri Sep 15, 2006 10:17 pm

hey guys, well my missing issuses are back again. i went to a track day today with the mini club and BD4's and the car went fine but as the day went on and towards the end of each run the car would start to miss. like the power was being cut by no spark. the tacho would jump around all over the shop and the car would jerk power coming on and off, it would only happen when the car was under acceleration. if i just reved the motor it would be fine but under load once it got over 4500...5000 rpm it would jump as mentioned. talking to one of the guys from bd4's who seems to now his stuff. he said it sounds like coilpacks and that he has witnessed this in another mx5 and other cars particularly with afew k's on the clock.

sound fair to me.. just want to ask you guys on here before i go buying anything and well... i think i might need some help as i havent dealed with this kinda thing before and im not sure where i can get one in under a week as the next track day is creeping up :shock:

thanks in advance

irwin

JBT · Postby **JBT** » Fri Sep 15, 2006 10:35 pm

Can you give everyone a quick update on the history of the miss, total km, when the plugs/leads were last serviced and what engine mods you have?

Russellb · Postby **Russellb** » Fri Sep 15, 2006 10:36 pm

Common problem on the NB
New Coil pack about $750 and avalible overnight to most places
Try mania or see if anyone here has a set that they replaced ( usally only one pack that stops working) If you havn't changed the Plug and Leads in the last 40 000 Km try them first ( much cheaper)

JBT · Postby **JBT** » Fri Sep 15, 2006 11:28 pm

Oh well, here goes another guess. At the track day I just attended, a guy with a Lancer EVO? was having the same sort of problem but only in 4th and 5th gear. No problems at all during acceleration at all revs in lower gears.

General consensus by the experts there was that it was an AFR tune problem because he had an aftermarket ECU or plug in but it was only tuned in 3rd gear on the dyno. The suspicion was that the \"estimated\" tune for the higher loads in 4th and 5th was probably out by a little bit and that it could be adjusted and dyno checked.

irwin83r · Postby **irwin83r** » Fri Sep 15, 2006 11:42 pm

car has 140000 on the clock, motor is standard internaly with a CAI and full exhaust. plug leads and plugs have been changed under a year ago.

the problem happens in any gear but only under acceleration or some for of load. if the car is not in gear or clutch is in it will rev out as normal.

the tacho also seems to jump around alot too... if that means anything or its just trying to show the mass change in rpm...? though rpm shouldnt be changing really as the motor is still spinning its just missing a fire.../???

coil pack is sounds like the fix.. but ill have to miss paint ball on sunday if i want to get my car ready for the next club track day.. bummer

irwin83r · Postby **irwin83r** » Sat Sep 16, 2006 3:56 pm

rang mania, they are putting their money (....my money

) on coil packs. so will be getting them through the week (so i guess it will be there money

)

will post up again with report on if it fixes the prob or not

thanks for the help

irwin

JBT · Postby **JBT** » Sat Sep 16, 2006 4:19 pm

Just looking at the wiring for an NA8 (NB8A the same?), it seems the tacho signal comes from the coils. So I suppose if a coil was cracking up it could send a really mad signal to the tacho whilst causing a less dramatic missfire.

Good luck.

Matty · Postby **Matty** » Sat Sep 16, 2006 4:25 pm

I believe Max Kirwan Mazda down here in Vic have worked out how to repair the coil packs at a much lower cost than buying a new one. Might be worth speaking to...