engine misfire, new injectors,plugs, filters, gaskets?

[USAFSTI]

I bought my wife a 02 wrx wagon Nov 2011. About 8 months into owning it we got a engine misfire code. Checked everything I could and found nothing. Reflashed the ECU and it never came back on. Recently we moved to Cali and the code became persistent. So I started researching and found it could be fuel injectors. When I looked it had STI pinks in it with all wrx parts. So first I ordered some used OEM wrx ones and installed them. The code went from 2 cylinders to all 4. So I sent all 8 injectors off the get cleaned and flowed (they were really bad) installed the wrx ones after along with new plugs, fuel filter and injector gaskets and now I am still getting misfire codes. It has always run fine and pulled normal. Where I am at now is either the coil packs are bad, valves are bad or ECU is bad. Any help would be awesome! Thanks in advance!

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[rocketperson7]

so you changed fuel injectors without retuning for them?

well there's your problem

[USAFSTI]

Negative i have a cobb ap and reflashed the stage 2 after putting the oem blue injectors back in

[rocketperson7]

ah, ok

are the misfires audible at idle?

try..

checking for vacuum leaks
cleaning the iacv
clean the maf

do you have a lightweight flywheel?

if you do end up replacing coilpacks, get teh grey ones

[USAFSTI]

No audible but kinda hard to tell it has solid motor and tranny mounts.

I have tried the best I can I think I will get a smoke test for the vacuum lines.

Yes I think it does have a light weight flywheel.

Which ones are the grey ones? The only ones I have found that are grey are the race ones and I don't got 700 for coil packs haha

[danger1138]

No , oem grey coilpacks.. They should read 'FKO186'...

[rocketperson7]

Originally Posted by danger1138

No , oem grey coilpacks.. They should read 'FKO186'...

yep

the grey ones came on teh 04+ WRX and the STi, you should then have your tuner add in some dwell for more horsiepowers
you'll use the sparkplug sleeves from the black ones however

lightweight flywheels tend to trigger false misfires
the way I could always tell if mine were false or not were if there was an audible misfire at idle

[USAFSTI]

Where can I get them at? I have been searching the Web and can't see any anywhere!

[Concillian]

clean off the cam and crank sensors, these cars are prone to having phantom misfires.

You can usually feel a true misfire. Not just hear it, but it should be pretty apparent when driving, especially if they're happening under boost.

[USAFSTI]

Originally Posted by Concillian

clean off the cam and crank sensors, these cars are prone to having phantom misfires.

You can usually feel a true misfire. Not just hear it, but it should be pretty apparent when driving, especially if they're happening under boost.

I have noticed that it happens often with these from research.
It drives and pulls on boost like normal. Kinda hard to tell if it's idling hard because it had solid motor and tranny mounts. I have notice a little smoke from the tail pipe a while ago.

[quazimoto]

http://forums.nasioc.com/forums/show...light=misfires

[USAFSTI]

Originally Posted by quazimoto

http://forums.nasioc.com/forums/show...light=misfires

Good thread I'm about half way done with it already guess I'll try the rest thank you!

[civhatch92]

Did you actually gap the plugs down? I replaced my plugs on my 2002 and thought they would be properly gapped from the factory.. wrong.

I was hitting misfire a whole bunch as well. Pulled the plugs back out, gapped them down to .28 and now it runs PERFECT!

[USAFSTI]

Originally Posted by civhatch92

Did you actually gap the plugs down? I replaced my plugs on my 2002 and thought they would be properly gapped from the factory.. wrong.

I was hitting misfire a whole bunch as well. Pulled the plugs back out, gapped them down to .28 and now it runs PERFECT!

No I didn't actually i figured they were as well.

[civhatch92]

Originally Posted by USAFSTI

No I didn't actually i figured they were as well.

The ones I picked up were BIGGER than .40!!!!
Definitely pull them out and check, I bet they need to be gapped down to .28 and then it'll be all good!

[USAFSTI]

Originally Posted by civhatch92

The ones I picked up were BIGGER than .40!!!!
Definitely pull them out and check, I bet they need to be gapped down to .28 and then it'll be all good!

What plugs are you using?

[civhatch92]

Originally Posted by USAFSTI

What plugs are you using?

I think these: NGK/Iridium/BKR6EIX/WRX/stock

[USAFSTI]

Originally Posted by civhatch92

I think these: NGK/Iridium/BKR6EIX/WRX/stock

I'm using the same

[civhatch92]

Like I said, pull them back out and gap them to .28

[USAFSTI]

Originally Posted by civhatch92

Like I said, pull them back out and gap them to .28

Howe did you compress them back to .28

[civhatch92]

Spark plug gap tool, auto zone sells them.
Here's a video.

HOW TO- Tune up, Gap spark plugs and understand proper heat range (Wechseln der Zündkerzen) - YouTube

HOW TO- Tune up, Gap spark plugs and understand proper heat range (Wechseln der Zündkerzen) - YouTube

[rocketperson7]

except you shouldn't be gapping iridiums..



when you break off the very very tiny electrode, you will render the plug useless

[USAFSTI]

Originally Posted by rocketperson7

except you shouldn't be gapping iridiums..



when you break off the very very tiny electrode, you will render the plug useless

That's why you done touch the electrode

[danger1138]

U can gap them without touching the electrode. You just have to be real careful while measuring the gap.

[civhatch92]

Originally Posted by danger1138

U can gap them without touching the electrode. You just have to be real careful while measuring the gap.

Word, worked perfectly fine for me. Never had any issues. Or just buy non-iridum and gap them if you're worried about breaking them.

Way I look at it: improperly gapped - runs like crap with misfires, broken electrode - worthless spark plug, either way something has to be done!