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Old 03-05-2008, 10:06 AM   #1
Destined2race
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Default Spark Plug HP loss help??

Hey i changed my spark plugs last night(wow its a challenge, not like hondas), I replaced them with the same NGK R's (they didnt have coppers), and this morning i noticed the car seemed to have less pull? Is this something that will get better as the spark plugs get wore in a lil bit? Everything was tight, so shouldnt be an install issue. I gapped them to .32 like it said? ANy help would be great. Im going on the dyno next week so i need to get my car in perfect running condition. Thanks
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Old 03-05-2008, 10:35 AM   #2
98EJ20
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What mods do you have?

I have stg2 plus a lil and I run .28 gap.
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Old 03-05-2008, 12:08 PM   #3
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I havent even changed my spark plugs. THX for the reminder. Honestly though ya the civics spark plugs are a breeze to change. Anyways post the dyno # and well c if your laggin or up there
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Old 03-05-2008, 12:16 PM   #4
Destined2race
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Quote:
Originally Posted by 98EJ20 View Post
What mods do you have?

I have stg2 plus a lil and I run .28 gap.
i have an APS tbe and a SPT short ram, but i had the same plugs and gap, and i noticed in instant lag when i punched it... it seemed like boost was going fine, maybe just not enough spark or sumn (since it happened after changing the plugs, obviously the culprit is the plugs ) Ill post the dyno numbers, but i dont wanna drive to chicago(200miles) to have problems or get a crappy pull... Thanks anymore ideas?
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Old 03-05-2008, 12:43 PM   #5
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Try closing the gap a lil. Try .030 or .028.
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Old 03-05-2008, 01:20 PM   #6
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Yeah...I'm not sure where you got .032 from.

I've always heard it was .030, which is what I gapped mine to when I did 'em over the weekend (coppers). Car runs fantastic now with the upgrade from platinums to coppers. Definitely back the gap back down to .030 and then see what happens....I bet it'll run much smoother.
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Old 03-05-2008, 01:23 PM   #7
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Quote:
Originally Posted by 98EJ20 View Post
Try closing the gap a lil. Try .030 or .028.
ok, but i dont understand why it would change at all... it ran fine with the same exact plugs at .32(wrx recommended gap), then i changed and now its lacking power. DAMNIT, why does nothing ever go right???????
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Old 03-05-2008, 01:26 PM   #8
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IIRC, bigger gap is a hotter spark but on a FI car it can be blown out. I remember reading that stock WRX gap is .028. I know they suck to remove, but try closing the gap up.
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Old 03-05-2008, 02:07 PM   #9
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Is there such a thing as getting ahold of a bad plug?
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Old 03-05-2008, 02:27 PM   #10
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I guess it's possible.

Maybe 1 isnt all the way tight? You need to seat that washer then tighten the plug, maybe its not totally sealed on one of them...idk....
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Old 03-05-2008, 02:41 PM   #11
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Weird....
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Old 03-05-2008, 03:48 PM   #12
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Quote:
Originally Posted by 98EJ20 View Post
IIRC, bigger gap is a hotter spark but on a FI car it can be blown out. I remember reading that stock WRX gap is .028. I know they suck to remove, but try closing the gap up.
well i went to autozone, and in there computer they said it shows at .032... i dont know, i talked to the guy at P&L and he said give it 48 hrs and it could correct itself from the battery being disconnected. Thanks guys for the input

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Old 03-05-2008, 05:06 PM   #13
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the partsamerica site shows .030.
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Old 03-05-2008, 07:09 PM   #14
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the gap is listed as 0.7mm - 0.8mm in the fsm

if you 'gapped' the plugs wrong and it is REAL easy to kill these plugs
then that may be an issue

also if you disconnected the battery then the ecu has reset and must relearn
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Old 03-05-2008, 07:58 PM   #15
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Quote:
Originally Posted by Arctic Penguin View Post
the gap is listed as 0.7mm - 0.8mm in the fsm

if you 'gapped' the plugs wrong and it is REAL easy to kill these plugs
then that may be an issue

also if you disconnected the battery then the ecu has reset and must relearn
that seems awfully far off from what everyone elses saying... and i was told. Anyways when i left work today i drove about 35 minutes, being easy on it and trying to let "break in". WHen i got to my street i slowed down in first and punched it.... it pulled hard and smooth so maybe it is the ecu relearning. Ill keep monitoring it though. I did remove the battery for a while so that couldve been the reset. Thanks for the help
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Old 03-05-2008, 08:27 PM   #16
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Did you unplug the negative battery terminal before changing the plugs? You could have just reset your ECU.
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Old 03-05-2008, 10:29 PM   #17
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depending on your tune, you may have reduced the IAM. if its stock, your IAM will be 8 instead of 16. so you would only be getting 1/2 of your ignition advance.

Try this:

take off the negative cable again, and hit the brakes a few times. fire up the car and take it out without getting into boost. get up on the highway or somewhere you can get into 5th gear. put it in 5th and back down to about 2000-2500rpms. watch your boost gauge and boost up to bout 5-7psi for 4-5 secs. then feel how the car pulls, that should advance your IAM back to normal.
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Old 03-05-2008, 11:57 PM   #18
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Quote:
Originally Posted by Destined2race View Post
that seems awfully far off from what everyone elses saying... and i was told. Anyways when i left work today i drove about 35 minutes, being easy on it and trying to let "break in". WHen i got to my street i slowed down in first and punched it.... it pulled hard and smooth so maybe it is the ecu relearning. Ill keep monitoring it though. I did remove the battery for a while so that couldve been the reset. Thanks for the help
0.7mm = 0.0275"

0.8mm = 0.0315"
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Old 03-08-2008, 01:09 PM   #19
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Yep, its your IAM. Do the Vishnu trick and you should be fine. I know because I have an 02 that had the same problem. Do what WeldingHank said and you should be good to go.
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