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Hey guys I know this is a issue thats brought up a lot it seems, ive read through some other posts but i still need some advice.
That being said, im a engine noob, just starting to fix things myself. Go easy on me
2005 9-2x aero. Bone stock (cobb short ram arrives tomorrow)
When i pull from 1st through 4th, i barely EVER notice the misfire. But when im sitting in gear, 3rd for example, going 50 mph, then put it to the floor, starting a 4k it will start to sputter. Usually stopping by 5500rpm
Sometimes its hard, others its not, sometimes its not there. But it usually will only do it during the described time, pulling from whatever gear i was driving in, not while launching to redline through the gears. The misfiring itself isnt noticed by my friends when i ask, but you can notice it when your the driving, so that might give you an idea that its not a hard sputter/ misfire, usually.
Okay, so I put new sparks in myself two weeks ago. And the problem was not there anymore for about a week, then it came back. The plugs i took out had about a .032 gap about, the ones in are about .030. I put in NGK Iridium IX (BKR7EIX). I put them in and tightened without a torque wrench, I followed a guide from on this site. Everything was done right and i took my time(never had to take apart so much stuff to get to plugs), the only thing I can think of is maybe they aren't set perfectly since I had to estimate the pressure. I now have access to a torque wrench if wanted.
-Where should I start? What do you think it it?
My next step as of now in MY mind are coil packs. Should I try and take everything back out and reset the plugs WITH the torque wrench? Should I try a different plug? Cooper? Should I do all that and get new coil packs?
They're used coil packs out of an 05 wrx in the town over, 65,000 miles on them, out of a totaled car. Should I buy them, or new? (Im 18 on a budget, working at a grocery store, my car is my love and gets all my money) Should I try the used set out? What should I pay for them IF i get the used ones.
*weird, my car idles a little rough, you can feel a little shake to the car when sitting, the the needle sits happy at 500rpm for the most part
-She runs really GREAT other than whats happening. I bought the car with 100k about a month ago, for 7200, beautiful shape and just got all 105k maintaince DONE. Inspected perfectly.
-What else should I try/ could it be?
I did run injector cleaner through two tanks about 3 weeks ago.
Any help is very appreciated! I'd like to get this thing running good, many performance parts I am waiting to order...
Send back that short ram. Won't do you any good - best to spend the money on up-pipe, down-pipe, or exhaust. The car gets plenty of air, it's the stuff around the turbo and the exhaust that holds it back.
Always, always, always go after the simplest solutions FIRST. 9 times out of 10, it's something simple - and you'll keep yourself from tossing money at the thing unnecessarily. Be patient.
Fuel, Air, Spark.
Before you do ANYTHING ELSE - go find an Autozone and plug in an OBD2 scanner. Pull your code, that'll tell you if the ECU detects an actual misfire. If you're not getting lights on the dash and you can't get a code, then chances are it isn't the Spark that's giving you problems. Might be a good time to take that refund on the Cobb short ram and spend it on a scanner for yourself. It will more than pay for itself over the next few years.
Pull the plugs, inspect the porcelain insulators for cracks. Re-gap to the middle of the recommended range, reinstall. You shouldn't need a torque wrench - I've done plenty of plug changes without one and never a problem. Just don't get all Conan on the thing. I've also found that a little bit of Anti-seize on the threads does wonders, 30k down the road when you go to change them.
That's the simplest check, first. If that doesn't solve it, then try and trace the misfire by wetting down the individual wires with a spray bottle and water. If it stumbles when you wet one of the wires, then there you go.
Wires and coil pack are integrated, IIRC. So you'd have to change it all at that point.
Then you'll want to figure out if you're getting a leak in vacuum or if the intake system needs looking at; the Air problem. I'm pretty sure it isn't a fuel issue if you ran a Techron or SeaFoam through the tank a couple of times. Could be there's some gunk in the system somewhere, but if you've been running premium and don't have issues anywhere else in the RPM band, chances are the problem is around the injectors, which gets you into that 1 time out of 10 that something ISN'T so simple. That's about when I'd double check all the easy stuff first to make sure I didn't miss something.
Last edited by Bryan (2012-04-25 19:34:13)
When was the last time the Mass Airflow Sensor was cleaned? If the answer is "I dunno" - get some MAF cleaner spray, pull it out, and hose it off with the spray.
Also (I've posted this on several other spark plug threads) - you should NEVER gap or check the gap on an iridium/platinum plug. The NGK's should come pre-gapped. The center electrode is hair thin and exceptionally easy to damage.
Not sure if I missed this while reading...but have you verified that it's actually a misfire with a CEL and code, or is it just that you can feel a stutter? Have you reflashed the ECU, or is it stock? The stock tune on these cars will cause the car to stutter under full throttle around where you are saying (not misfire, it's just a stutter). It happens because the engine is switching between closed loop fueling and open loop fueling...if you're wanting to learn more about these cars, this would be a good thing to read up on.
As for the spark plugs...I will be impressed if you get a torque wrench on the plugs. Here's what I do...screw the spark plug by hand until you feel when the crush washer first makes contact, then tighten some more with a wrench, and you'll feel when the washer is completely crushed because it'll get a lot harder to turn. Get it to that point, then snug it up a hair more. Unless the spark plug is way loose and on it's way completely back out of the cylinder, this probably isn't your issue.
Oh, and the idle is relatively rough in these cars. Just the way they are.
Last edited by kornfeld (2012-04-25 20:20:29)
Also...are you saying the car was stuttering to begin with; then it went away when you put new plugs in; then the stutter came back after a week or so?
Or did the problem only come up after you put the new plugs in?
I changed the plugs to begin with to attack the problem.
No CEL and havn't plugged it in, stock ECU. I plan to keep the intake, it has good reviews and i plan to do A LOT to this car, so that short ram isnt going to hurt, but yes I know they aren't meant to add power on these cars.. $150 isnt killing me.
No I have not cleaned the MAF
I CAN get new coils for $160..
So, start with taking them all back out and replacing them? Clean the MAF? And...what else? What supporting mods are going to possibly help this the most? I have the money and was planing to order a uppipe and downpipe next. Wait to see how they affect it?
I appreciate all responses and im still learning so thanks for the help, as for the idle, thats what i thought too my other subie was the same way..
Clean the MAF first. kornfeld brings up a good point about the fueling - and if you're not getting a code or a CEL, then wait until you do more tuning to the car - and study up.
Im going to clean the MAF tonight and put the ram in, plan to order down and uppipe this weekend. Ive been learning a ton and I really love it. We will see how this goes, might reset the plugs this weekend too. I always run 91 or 93, 93 currently in the car (only one 93 station on the area)
I changed the plugs to begin with to attack the problem.
If the stutter was there before and after changing the plugs, then they probably aren't the problem. It's not a guarantee, but if you have the same problem before and after changing something, then that something probably isn't causing the problem.
No CEL and havn't plugged it in, stock ECU.
Then you probably aren't misfiring. It's probably the stutter that is well known on these cars as they transition between CL and OL fueling.
I plan to keep the intake, it has good reviews and i plan to do A LOT to this car, so that short ram isnt going to hurt
It might hurt. There are many mixed reviews on intakes, and the single universal thing is that you won't know if it's hurting your car....until it hurts your car. Changing the intake can cause the engine to run excessively lean or rich. I think the Cobb intake is supposed to work without a tune, but without a wideband O2 sensor, you won't know. As you said, the only thing it will do for sure is not improve performance. So why risk it?
I CAN get new coils for $160..
Don't bother. You probably aren't misfiring.
So, start with taking them all back out and replacing them? Clean the MAF?
In my opinion, no to the plugs. Start by resetting your ECU. If this fixes the issue for another week and then the stutter comes back, it's probably your tune and not your plugs or coils. It wouldn't hurt to clean the MAF as well, but either way, start by resetting your ECU. If you aren't sure how to do this, this would be a great thing to search around for here and on NASIOC.
I appreciate all responses and im still learning so thanks for the help
No worries, welcome to the forum. My number one piece of advice: do some more reading before you start putting parts on the car!
Here's a great place to start:
How do you know it's misfiring? Are you receiving an error code, or is this a guess on your part? If the latter, what's making you think it's a misfire?
I've go sure money on CEL P0171 after intake is installed.
You're on. Worth a buck.
Time frame: CEL >1 month after install work for you?
Sounds like he's running Mobil 1 to me.
I DO think it could be shitty 93. Theres only one station in my town with it..might go back to 91.
But im pretty sure ive got the problem nailed for now
Random question someone might see, is it worthwhile to put an 09 catless uppie in my 05 ? Or should I just go with a true after market one. The 09 one is 35 bucks from a friend.
Opinions? Downpipe in the mail. Lightweight pully too.