Evening All

Had a bit of an ongoing problem for a long time now. My car develops an annoying miss fire at times.
Originally when this happened it got the camshaft sensor changed which was the problem and all was fine for ages.
Now after numerous times changing the plugs and checking the leads and coil packs it keeps coming back.

It seems to work for around 4-6 weeks when i change the plugs and then begins to missfire again. Particulary in higher gears when accelerating.

I only really use the car now and then at weekends as it is a second car. Anyone got any ideas?. I have asked this many times but maybe someone will think of something i havent checked.

Getting fed up of taking it to the garage ever 6 weeks.

Could it be:

• Where it is not being used the plugs are coking up and becomming dirty far earlier than they should?.
• The VTA Dumpvalve causing it to run lean and where its not being used regulary speeding up the coking process?.
• Plug Gap?, Currently 0.6mm.
• Or coilpacks, leads. Can i check this myself?.
• Some sensor somewhere?.

Any help greatly appreciated as I really miss a good blast at the weekends. Currently I have to drive it like a granny or take the company car. If it helps its an MY93 WRX.

 

may sound daft but have you tried covering the vents on the bonnet if left standing for any lenght of time,i had the same problem and believe it or not when the car was parked ,there was a tree nearby and when the rain came ,hey presto straight down the tree directly down the air intakes and one very damp engine bay,creating intermettent misfires.one bow saw later and no more misfires.cover them vents if leaving out for long periods of missuse

 

sounds like your coilpacks, i changed my plugs hoping it was just those that needed changing. ran fine for a week before it started misfiring again. shelled out for a set of coilpacks and now she is running just swell

ps maybe the dreaded MAF SENSOR also

 

Last time I had anything like that was with a Pug 309GTi quite a while back, stuck it on a rolling road and it turned out to be the plug leads breaking down/shorting out at about 5000 under load.

 

worth a go, although 90% of the time it is garaged. although sometimes it is left out after being washed.

I expect the cold damp weather doesnt help wether it being garaged or not.

 

coilpacks sound like they are worth a look too then.

Are they easy to change?.

 

yeah best to remove the water bottle on the right hand side and the air filter on the left hand side, makes it a lot easier to get at them

 

thanks, will have a look this weekend.