Hi everyone, my 95 wrx has developed a misfire on boost at about 4000 rpm , i have recently fitted , polar performance chip , boost gauge k&n panel filter , i have done search on here already and found that it could be the coil packs and plugs , I currently have NGK PFR7G plugs , i have not gaped the plugs , but it nether misfired before , but since the chip , do you think this could be the cause of the misfire? it has only started doing this since the mods above,
any help much appreciated, cheers

 

gap the plugs to 0.7mm it is most probably misfiring because it is running higher boost.
tbh plugs should always be gapped properly before fitting.
When you regap th plugs check the end of the coilpacks for cracks as well but do it carefully or you may crack them yourself.

 

will check plug gaps and coilpacks , cheers

 

my 95 Ra did the very same after the polar chip but unusually for me and thankfully just a new set of plugs cured it....mine where gapped to 0.65

 

what boost is it running ??

 

If you go to Polar,s site there is a section for problems after fitting. But i think you have the general concenus its the plugs. Have you inspected the coilpacks for cracks?

IIRC it raises boost to 1.1bar?

 

my plugs are gapped at 0.8 and i'm running 1.3/4 bar do many people get problems if they not gapped at 0.6 or so??,mine are sound

 

I didn't get any problems straight away , as today was the first time i have run it with the chip , it was going fine, then i come on boost again and it started misfiring , could it be that when a coilpack gets hot, and it doesn't work as well or something like this , but the plugs definitely need gaping as i just put them straight in , not sure what gap they come with as standard? , cheers everyone

 

The arly coil packs can and do break down under load, be worth checking for cracks etc.

 

as above pull the boots off carefully and check for cracks,some drop to bits when you do this.

 

mine misfired when the polar chip was installed checked the coilpacks under the rubbers & they fell to bits these are more than likely the problem & plug wise i was recommended to gap them to o.6 think standard is 0.7

 

Removed coil packs and they are all cracked -One is in bits , is it best to buy brand new ones or second hand , i can get new ones for £195 , does that sound alright, cheers

 

best to go new mate if possible but there not cheap i paid 65 quid each from camskill but think david at API does them slightly cheaper i think the oe brand is Diamond

 

Any one tried these , is this a good price ? Subaru Impreza Legacy Coil Packs Upgrade (Brand New) on eBay, also, Subaru, Car Parts, Cars, Parts Vehicles (end time 06-Jul-09 10:28:48 BST)

 

Not doubting the trader but i thought Legacy coil packs were held on by 2 bolts no t 1 (i may be completely wrong though).

you can buy 2nd hand just as long as they aren't cracked imo

 

Impreza coil packs have one bolt fitting and Legacy 2 bolt. That internet seller is so good he doesn't even know the difference.........

Genuine are the way to go, we have good stocks and are very competitive for price. One of our customers had aftermarket ones supplied that lasted less than 6 months, he's still trying to get his money back.

We used to sell used ones, but found variable results - so stopped.

David APi 01926 614333

 

ive had a misfire on mine for a while now, tis a round 4k too. thing is, ive replaced the coil packs AND the plugs? an i still av it? any ideas?

 

Sounds like a fuel cut cos there's something else wrong. get a diagnostic done.

David APi

 

Same thing happened to me after fitting the fujitsu chip.
Baought a set of X-Spec coil packs from ebay 195 free postage - all is perfect and has been for a year now!!!
;->

 

Right changed coil packs and seems to be fine now, cheers everyone ^^^.

but straight after changing them the car seemed to have lost a lot of power, and it turned out to be the coil pack had come unplugged , i drove the car around 4 miles at about 3k rpm until i realized , do you think i need to change the oil now as petrol would of mixed with it or would this just evaporate in the hot engine , i only ask as only last week i spent £50 on new silkolene 10w-50 pro-s and don't want to change it , any help much appreciated, cheers