tizard99

MY K-reg wrx is not well, seems to be mis-firing or not firing on one cylinder. Revs up fine, but under any load not happy!

I'm thinking its either coil problem (has individual spark plug coils) or ECU not working properly. Maybe even a leak/blockage.

Anyone any ideas from experience?

Many thanks,

Tizard99

Richiehash

cheap but dirty way to sort it out.first after one of the misfiring runs remove the plugs. check them, one will be a different colour either glazed (pale colour, shiny,often greenish) or fouled (black sooty or oily) this is your problem cylinder.swap this plug for a new one and check the coil pack resistance figures against the others (this may show up a bad coil pack).
try driving again if the missfire is still there swap coil packs with another to see if the missfire moves,if it does try a new coil pack( or one you can borrow from a friend) this should sort it. ps if you can get a compression tester take readings on the cylinders while the plugs are out just in case the missfire has done some damage like nuked a piston.
hope this may be of use
richie
ps you may find nothing wrong but the miss just goes after all this, in which case it was a bad connection cos coil packs can be funny like that

[This message has been edited by Richiehash (edited 07 June 2001).]

tizard99

Cheers Richie, some good ideas there.

Any others?

Tizard99

Adam M

The minute I hear older cars doing this, I immediately think coil packs.

Difficutk to tell which is which, try changing one bank at a time.

Fixed it immediately on my old car, and seems to be a very common fault.

Surely much more likely than an ecu fault?

tizard99

Thanks for all the ideas. I've since nipped over to Scoobysport, who sorted it straight away and amazingly it wasn't any of the suggestions on this post or what other people in the trade said.

I won't say here what it was as not to give away any of their secrets but if you find yourself in this situation give em a call.

Tizard99

mul

had the same problem with my MY94 WRX.

take off all te coil packs and pull the rubber seal off the end of all of them one at a time. Look for any craks or splits around the end of the pack.

The end of one of my coil packs disintegrated when i took the rubber seal off, but once we had wrapped insulating tape around it, it was fine.

Its probably worth changing the plugs, fuel filter and resetting the ecu if none of these have been done for a while

hope this helps

chris