engine miss

[Guest]

ok this morning i drove to work and noticed my car was missing quite bad.stoped and pulled over and turnd the car off

opend the bonnet to check all leads and every was still on,everything was sweet.

startd the car and drove to work.after work i was driving home and it started again but this time abit worse,.turnd it off again and now seems to be sweet.

havnt had a GOOD looking over it yet cause its dark already,

things i should check?

-plugs

-coil pack(not sure how to test this)

-leads(all of them still look fine)

-afm

my motors done 14000ks now and this is the 1st time its done it,so im guessing its ether the coil pack or plugs.

is there anything else i should check?

cheers alex

[WRXONP]

hope it hasnt broken a tip off a plug !!!

pull plugs and check

if one side of the coil drops it will loose 2 cylinders as its wasted spark

it missing on idle and all the way through rev range or only at high load?

can also be a broken down HT lead u need a multimeter to test

[pauly12]

my car is having the exact same issue. i suspect the issue is related to spark plugs.

The issue ive found isnt repeatable it just occurs sometimes, for me it lopes at idle which it never used to, and from light throttle to open throttle it misses badly...sometimes, under full acceleration its sweet, this is my scenario. im gonna pull my plugs tomorrow so ill post back what i find .

[Guest]

just underload bro.driving along in 3rd you can feel it.as the revs got higher you could fell it more.

guna drive it tomro and see how it is.

[WRXONP]

chances are if its running fine off boost and shit on boost its more than likely plugs..replace them theyre cheap

[8e4r]

 WRXONP']

chances are if its running fine off boost and s*** on boost its more than likely plugs..replace them theyre cheap

+ 1

[quote name='sti8u said:

just underload bro.driving along in 3rd you can feel it.as the revs got higher you could fell it more.

guna drive it tomro and see how it is.

If it's happening under load it's very likely the coil plugs/pack need attention, quite a common issue with the older EJ20G engine which uses individual coil plugs, housing is prone to cracking. But the wasted spark coil pack design (WRX versions 4 through to 6, EJ20K and EJ207 engines I think?) will cause similar issues and symptoms with age. If the spark plugs haven't been changed lately it might also be a good idea to get them sorted at the same time.

[WRXONP]

he has ver 3 - wasted spark

HT leads will brake up and missfire under high load when old

you need to test resistance with a multimeter ..and also move the ht lead around and watch the multimeter for brakes in continuity

on that note though

do you even know what plugs it has? how old they are? what the gap is? a plug can "look allgood bro" when you pull it out but it still doesnt mean shit all

what colour are they? what they look like?

[Stoffa]

ive got a spare coil pack off v5 sti if thats any help

[WRXONP]

ver5 different to 3-4

[hijacka]

 sti8u said:

ok this morning i drove to work and noticed my car was missing quite bad.stoped and pulled over and turnd the car off

opend the bonnet to check all leads and every was still on,everything was sweet.

startd the car and drove to work.after work i was driving home and it started again but this time abit worse,.turnd it off again and now seems to be sweet.

havnt had a GOOD looking over it yet cause its dark already,

things i should check?

-plugs

-coil pack(not sure how to test this)

-leads(all of them still look fine)

-afm

my motors done 14000ks now and this is the 1st time its done it,so im guessing its ether the coil pack or plugs.

is there anything else i should check?

cheers alex

Fuel pump..

[Guest]

hmm nah dont think its the pump ah.i got a intank walbro

[Stoffa]

AFM?

[marc]

think I have a coil pack floating around if you think thats your prob

[Divine]

Same problem here.

Same engine.

Will replace spark plugs and report

[Guest]

ok update.

check all my plugs and still look mint.but they have 15,ooks on them when it was rebuilt so i might replace them

got the guy at my work to check the coils and he thinks there still sweet,

afm seems quite happy atm.i spray abit of afm cleaner on it every couple weeks to keep it happy.

defintly can notice the miss at about 5000rpm on boost

[Stoffa]

a fu%ked AFM still LOOKS sweet, doesn't mean it WORKS sweet

[Guest]

when my afm plays up idel changes,i can tell by the vacum on my boost gauge.this isnt happening atm.so it seems algod,

[rex-leggy]

an afm shouldnt play up

and did you use the walbro supplied filter sock? ive heard bad thing about them.

[WRXONP]

walbro sock will cause missing (lean mixtures) at high revs with low gas level

if the plugs are copper then 15k is way past their used by date

u should know by know u dont just look at something and say yeah its sweet... theres more to a spark plug then what it looks like.. u check spark gap??

[Guest]

nah definlty not the walbro.as its been in there since rebuild and this problm has only just stared.

will replace plugs today and update,

[xsvpwr]

sorry to hijack the thread but how do you know if your spark plugs need replacing if you don't know when they were last done?

[Guest]

lol they werwe done on my rebuild

which was exactly 15 430ks.

[WRXONP]

what plugs where in it? cheap ones only last 10 k odd. platinums are supose to last 100k

[hijacka]

 WRXONP said:

what plugs where in it? cheap ones only last 10 k odd. platinums are supose to last 100k

Exactly my thoughts to,

Just a guess but Sounds like it could be blowing the spark out?RE: missing at high rpm and probably on full boost aswell.. could try setting the plug gap to 0.8mm or 0.7mm..Once you get the right plugs that is

[xsvpwr]

 sti8u said:

lol they werwe done on my rebuild

which was exactly 15 430ks.

I was asking for my own vehicles benefit that's why I apologized for the thread hijack.

Don't know when they were done or whats in there but last owner was fastidious so I imagine will be platinum or iridium.

Will pull them out today and have a look-see, what would be the things to look for to know what condition they are?