Running ruff at idle

[wrxboy]

Ive got my v4 wrx, i took it from oamaru to nelson and back(for th fours and rotors) did over 1700km all up. Ran amazingly well. got home turned it off and it sat for couple of hours. Got back in it to pick misses up from work and it idles fine then runs on like 3 cylinders/misses badly then runs good then does again and it carries on. once over 1500 revs it runs great boosts fine etc just at idle it doesnt run properly. the only thing i did differently while i was away was i had to use a tank of 95 instead of normal 98 as nelson doesnt have 98 lol

I havent had a chance to look at it yet as im too busy doing house renervations but thought you guys might have an idea of what could be going on???

Will have a look this week.

Any advice will be great.

[Roo]

More brakies

[wrxboy]

?

[Marky]

Simple sh!t first

Clean the afm, check for vac leaks, check the bov seals properly, reset the ecu just to make sure its not just being a dick to spite you

[hijacka]

Does it idle ok when cold and when at normal temp rough?

[wrxboy]

 hijacka said:

Does it idle ok when cold and when at normal temp rough?

When first started it idles fine but as soon as you totch the accelerator it drops revs and misses.

will check the obvoius shit at w.e.

Cheers

[wrxboy]

Started today ran fine??? took for drive was fine, checked for codes (nothing) cleaned afm etc. weird....... will just have to drive and see what happens.

[titian]

Failing temp sensor. ;)

[wrxboy]

 titian said:

Failing temp sensor. ;)

Hope not lmao replace two years ago bowt 10,000km ago with new item.

[Roo]

Won\'t be temp sensor, this is an actual misfire

[4G63B8]

my subi did that, was one of the spark plug leads not making contact properly was weird as hack!

[wrxboy]

 4G63B8 said:

my subi did that, was one of the spark plug leads not making contact properly was weird as hack!

Me and roo check all that the day it started it. last w.e it drove mint, started 5 mins ago running shit again just at idle.

[Roo]

Needs nos

[Stodart]

High tension( spark plug) leads/coils can do intermittant funny things when failing.

Have never had problems with Subarus but when in Australia 24 years ago had a 74 Holden HJ 202 panel van the spark plug leads were breaking down and it wouldn\'t run, ok cold but soon as it warmed up it would miss badly on all 6. replaced leads and it was fine.

One of the worst vehicles had the displeasure of owning the only vehicle to die (seize) while driving normally with no warning. probably took the top off a piston which they were notorious for. never looked just got another one (202) and bolted it in

Had an old Austin ute as a farm truck 40 years ago and it was doing similar stuff,replacing ignition coil fixed it.

Also check inlet manifold gasket/s, may possibly be leaking.

[Roo]

Has a boost/vacuum gauge and the vacuum is okay.

Need to catch up with him again so I can put my multimeter on the ht leads

[wrxboy]

By leads have now been checked and are mint!